I worked at a Coach outlet about 10-12 years ago. At that time if people would come in with a small stain or mark on the bag we would try to do a spot cleaning for them. We would just use the same coach leather cleaner and moisturizer that is sold in the stores though. We also could do little things too like replace a turnlock closure. If you needed a major cleaning then yeah you could just take it to a retail store and ask them. If it's suede definately stay away from the drycleaning service and from dish soap (although I have tried this with some of my other bags).

Velvetine although it was a long time ago when I worked for them we never required receipts. We could tell by looking at the bag whether it was real and that was good enough. I doubt the retail stores would require any sort of receipt to send one off but I have actually never had to have any of my bags repaired so I'm not certain. They all have individual serial numbers imprinted in them so they may do some sort of lookup to verify their authenticity.... this is just speculation though.... they may not check. You could just take it into a store and say it was a gift and see what they say.