Mobile aircon service in surrey/Berkshire -recommendations?

[BMWBen]

The missus seems to have broken her air con - only blows room temp air when you run the compressor, either needs a regas or a leak fixing I reckon. Took it to kwik-fit (I know, but I thought this was simple enough for them, and they do have a cooler aircon promise) who couldn't find the compressor (car is a smart roadster), so looking for someone who actually knows what the hell they're doing.

Any suggestions?