May be they check your temptation level
If they realize they cannot force you to pay own money and you have enough patience, they will stop bothering you with this damn own money. And as far as their way to deal with customers is concerned, in this country there is no business or work ethics. We are all in it together as a nation. We do our jobs to earn pay cheques, never concerned about the honesty and love for work. There is nothing with the name of job satisfaction in our minds. We are proud of the fact "kaam kuch nahi tankhwa itni ziada". Dealers are the same dear friend.