HSRP plate installation - My experience

Booked my appointment through hsrpmh.com and the agency for my area was FTA. There was confusion about the location as the address on invoice and the location shared with maps link ons sms were different. Had to call the customer care and confirm about the right location. I reached the location and I was told by the guy there that they can't rivet the plate directly to the car, a frame is needed. I din read about it anywhere and felt like it is a scam. Called the HSRP customer care and they were clueless too and couldn't confirm if plate cannot be rivetted to the Car's body. As I did not want to waste my time, asked him to get the frame for which he charged 500/- (Available for around 300/- on Amazon). The fitting process took 10 mins. Later I got to know from a friend that the frame is not necessary and it should be optional.. Though the process was quick, the fitting guys are taking advantage and scamming people to make some quick money or they seriously are not trained. Sharing so that you are aware about this if going for the HSRP plates fitting.