I sympathize with you as others have done. And I will endorse what @Xulfiqar and others have said. You have already said that you don't mind the money spent but certainly you did not get what you paid for. On this point I am on your side.
As others have said that we need to hear from @dani_kk. What I seem to understand from this thread is, were you ripped off, or, did @dani_kk actually do the work correctly for the price paid? Now here is the thing with old cars. Everything is 30 years old; when one part is replaced in a series of parts the next weakest part will break. The owner may feel that the shop or mechanic has done a bad job. But that is a fact of owning old cars. The other thing I get to feel from the invoices shared, the prices seem OK. This is an old car and one sometimes has to pay a bit of a premium for finding hard to find parts. However what is not known if the parts are new or good used second hand ones. When I restore cars, I go for new parts from overseas but that is a different story. BTW, I have had instances where brand new parts have failed a few days after fixing. With 30 year old cars there is the after market parts that one has to contend with. Not all after market parts are created equal.
After seeing your video showing the very low idle, it seems that when you took the car it did not have this low idle problem and that began a few days later. I say this because if the problem was ther, you would not have accepted the car. So would I be right in saying that could it be possible that when the car was repaired, @dani_kk test drove the car and it may have seemed fine? During the test drive it did not misbehave and perhaps the drive was too short for the temp to reach the 70% mark. But once the overheating issue was discovered it should have been systematically checked and corrected:
You have written: "After 2 days i planned a trip to murree as i needed to check the car, and upon driving a steep curved road, i found the car was over heating again, i came back to Islamabad and called danyal bhai and told him the whole issue about car overheating again. he said there is no issue as this car once overheats will overheat and shutdown, if the needle got up and then again came down, it means there is no issue, i agreed." This is total BS. A properly sorted Diesel car does not overheat no mater where you drive it.
If I was you I would chalk all this as a learning experience. In my case I do all the work myself and there are times when I have done the work to the best of my abilities and a problem does appears after a few days. Now since I do my own work I can pretty much guess what happened. Sometimes, it may be a failed new part I fixed, sometimes it is the next weakest item in the line, sometimes it is something totally unrelated. That is the way of old cars.
On the plus side, one does not give up. One keeps on working away at the problems and once everything is sorted the car becomes very reliable. In the process, one learns the vehicle inside and out. In my case after I rebuilt my 35 year old car it became my daily driver and I began to prefer using it over my modern vehicles.
