Did exactly the same thing after 2 months of having my 147 - almost in tears! (sad I know..)
If it's any help I used a company called chipsaway. Their a franchised operation all over the uk...email firstname.lastname@example.org for your nearest operator.
Anyway, they came round to my house in the van, took the wheel into the van, sanded it, primed it etc etc, and I couldn't tell you where it was damaged. Perfect. And a good price as well - less than 50 quid! (obviously dependant on how bad it is
A lot of dealerships use them for their own work so they normally fit you in between jobs, or at weekends - well recommended though!