HELP - Mineral white E93 - needs minor paintwork

[JetskiJezz]

I've just bought a mineral white (metallic) E93 M3.
Unfortunately a couple of days before I brought it some to**er decided to put a key down the side.
It's thankfully not the deepest scratch, but it's still visible and runs down the top of the door and into the rear wing.

I bought the car knowing it had this to do and I have spoken to a very trusted local body shop but I've used on many cars in the past and have booked it into them to get the work done.

They just call me to tell me it's not as straightforward as we originally thought and that they are going to be struggling to get an exact colour match. They haven't done any work on my car so they suggested I pick it up and find someone who done work to this particular colour and knows exactly what they're doing with and how to deal with it .

My guys have done 5 separate test panels and not one of them is getting them an exact colour match so it is causing concern. They know how fussy I am, so they said they would rather not paint the car than do a job which none of us are going to be happy with.

I would love to know if anyone had any joy in painting one of these. PLEASE HELP.

THANKS