Sounds like your keycards have had a hard life - I have a 2001 Lag II and both cards are intact although one started to rattle but before it failed I sent it of to Gary at keycard repair and got it sorted for £25. This has already been mentioned by Dave in a previous post.
It may be possible to have your unprogramed keycard programmed to suit but for obvious security reasons it may not be possible.
it is possible to programme a unused virgin card , renault cant do it , but we use a different method . you must be certain it has never been programmed before though , there are some rogues on
selling used ones with new blades , be very wary