I had the same issue.
Managed to come across this company: https://automotivecompressor.co.uk/epages/eshop931745.sf/en_GB/?ObjectPath=/Shops/eshop931745/Categories
They wanted £450 up front, payable by BACS (no cards) so was very nervous. They had plenty of good reviews so I took the gamble and it paid off!
They can refurbish your old one too (may be cheaper...not sure) but they supplied me a new/reconditioned one and it's fitted and working fine. I've had the car back for about a week and the air is cool again.
The labour from my garage to fit was still £400 so the whole job isn't cheap but it's cheaper than £2,400!