I recently got a beautiful new miu miu napa leather bag on eBay, not sure what the name of it is, but I believe it's authentic. the leather is gorgeous and all the miu miu signature stuff looks right. anyway the only problem is i'm having trouble with the lock (it's the same kind that's on the coffer). i know you're supposed to push the two knobs together, but it gets jammed/stuck really often and only works after fidgeting with it rather painfully for like ten minutes or more, if at all. i'm afraid to close it when i'm carrying it around because if i can't open it my stuff is stuck inside. is there some "lock mode" that it is on? do any of you have any tips to get it unstuck and run smoother? also, if there's an actual problem with the lock, would they fix it if i were to take it to a store?