Sorry to say but he misguided or you can say lied to you. I will answer one by one.
1. ("according to him, the buyer came to him and asked the price of a front camera for corolla. the price was quoted along with installation charges.")
Ans: That is Correct.
2. ("when they saw the car they said that you can not install a front camera in it (it doesnt come with the grip required to do so. These grips are hard to find and cost anywhere between 500-1500 rs from company IF they have them).")
Ans: After wasting two hours by installer and slicing two to three wires behind the infotainment System and after not finding the AV in input and making a hole in monogram, pasting the front cam with a mixture of Elfy and ground soil, shopkeeper made an excuse that " Altis mein front camera install nai hota" they thought that there might be a grip present in the back of infotainment system with a label of front cam and i thought as they installed cam before so they know how to do it as one of pakwheel friend suggested this shop because he installed same front cam in his grande, the installer then asked another installer of nearby shop about this infotainment system and he told him that he had installed front cam in this infotainment system of same car model before. he told my installer that you need to take input from one of these pin but he also forgot pin number. Still installer didn't manage to find the pin. Let just say that installer and shopkeeper didn't know the pin number, shouldn't they do it as a courtesy as we finalized the price before and i came to their shop as a customer. Am i asking something out of the world? After my arguing in the middle of installation that why would i pay Extra Rs 500/- to find the pin number, it is not my job it is the installer job which i am already paying as a fitting charges, they told me no grip is present behind so basically they are hiding their negligence in the name of Grip by saying that company didn't provide . Should i pay for the teaching of installer too? Many people will agree on this. Don't you ? What do you think, now they know how to install front cam, will they charge extra to next customer of front cam too or they send infotainment system to the mechanic again for the finding of pin number?
3. ("he did the alternate and sent it to electrician to get the wire soldered directly to the pin. which can be seen in the picture. the extra charges are the standard for what electricians charge for such jobs. ")
Ans: They didn't solder anything . You can see in the attached picture clearly . Soldering need silver copper wire and there must be a mark of joint due to soldering . If you need to join two wires , will you do twisting of copper part and taping or you use soldering to join two simple cables?. They are just justifying Rs 500/- in the name of soldering. The Electrician just took a jumper cable specially designed to take input from a pin ( Hardly available for Rs 10/- or may be 5) and joined the required wire to it. The arrow shows in the picture is just a grounding by unscrewing the screw. What i all said is clearly visible in the picture. If the installer know all this, he will surely do that very easily. Don't you think?
4. ("As per him, the misunderstanding came from not knowing the exact model of the car as the buyer did not mention it at the time of asking the price.")
Ans. Are they not sitting in the market. Is that not their responsibility to ask? or they are just the newcomers not knowing the business well. I am just a layman, i don't know that which things are required for installation. They are suppose to ask me . Let just say that they forgot , shouldn't they tell this after seeing the car and before start installing anything? They told this after not finding AV in port. This is called unprofessionalism.
Forget everything, let just say that they made a mistake, shouldn't they rectify it by paying to electrician by themselves? or they should start abusing and misbehaving me for asking their responsibility. Same Front cam is selling for Rs 1500/- in lahore. You can check it by visiting main 11 generation thread where people coated the cost of front cam and you better know that they have a good margin of profit in each device. Thank God i do have the right infotainment System with AV in port in my car else they ripped off my car by installing everything and in the end they will say, oh you didn't mention that you don't have infotainment system of our required specification or even you dont have the infotainment system at all.
If they shouldn't do anything which i said then i will suggest my pakwheels friend that before going to Disco Music Saddar Rawalpindi, everyone should do their homework by knowing everything that you want to install from them . even the IC numbers of electrical components and grips, how to install that , what are the requirements, what are the ratings and you should tell all this to shopkeeper or else be ready to get screwed. Now you know that how much i am pissed off by ripping off my brand new car and still you are justifying them.
Eagerly waiting for your reply buddy.