It's like this, where you scratch the panel off to reveal the code (usually an alphanumeric sequence of 4).
Yes they will provide you the code - but you have to go in person to the dealership, provide proof of ownership, such as the registration document (or equivalent in your country), plus some ID and proof of address where the car is registered for example and maybe your driving licence or similar. Then all they have to do is look it up on the PSA database. They will charge a small fee (about £15-£20 over here in the UK), but you should be able to get 3 bits of info for the fee - the confidential code, the actual Key blade code and one other bit that I've forgotten now!
If they tell you different, complain to Head Office and they will help you out and probably talk to the dealer for you. Lack of staff training I think. It's good that they are being secure and cautious, but if you are the legitimate owner and have the proof, they are perfectly able to help you. Many people over here have had to do this.