Still not getting help

My car battery was flat for a few weeks so when I bought a new battery on the radio it requested Authentication Key so I went to Renault Hermit on where a lady with too much attitude assisted but the password she gave me was for the old radio as 2years back the radio had a problem where Renault called us to come change so she said I need to go back to the dealership where we bought the car .I then advice her that Melrose Arch has closed down and she said she can't help. Therefore we called the callcentre who again said we need to go back to the dealership. ..So my issue is what should we do know Melrose Arch dealership closed I'm sitting with no radio navigation system etc and Renault cannot help me its really is fustrating