I've just had a similar experience. Keycard falling apart so got 2 new ones from renault, only a one week wait!.
Anyway Tested the emergency key on my 53 plate 1.9dCi and it didn't work. Went back in and the dealer starts saying things like "have you had the door replaced?" "the only way out of this is for YOU
to get a new door lock!" (remember at the dealer its always the customers problem!)
Only reason I checked is I got a new key with imobiliser for a Clio 2 years ago and it didn't fit the physical lock when I came to try it. ("you bought this key 10 months ago with a 12 month warranty , obviously this is now out of warranty because its an unreasonable timescale to complain in...." h*****s , pontefract)
If you get a replacement card from renault which seems to be a monopoly industry
- Check the emergency key works, outside the renault dealer, or outside a nice warm house
, not halfway up a snowy, dark, windy hillside in wales, when the key battery has just gone flat......