Sorry buddy for bad experience. But the problem here is you are at fault. You are not supposed to let anyone sniff your hard earned money till the job is donw to your satisfaction. Also cha sultan has ALOT of jugaari and 2 number people who should be VERY closely observed. ANY type of poshish work takes 2-3 hours. If they have to stitch the covers of your choice u are supposed to take car home and come back after a day. Installation only takes 2-3 hours MAX including door panels, usually door panels take another extra house so the glue takes it time to cure.
Now that you have made the payment there is very little to nothing you can do.
You mentioned about using screws rather the original OEM tabs to reinstall the door panel. If i were you that guy would have been using screws to chew his food instead of his teeth.
The damage is done. Please do share pics of bad experience, the car and the bad workmanship.