First Polo... Please Help!

[Polo99]

Hi, I've just bought my first polo having already owned a golf. It's a 1999, T plate and a bit of work in progress. My first problem is the boot lock doesn't work. The key seems to fit and turn right in the barrel but won't turn left to lock. I think it's the lock cylinder housing and pull rod that needs replacing. Does anyone know different? Or could anyone tell me where I could get this replacement part? It's going to drive me mad if I can't lock it!

Thanks!