I hope you can help. I have a 2004 Ford Focus with air con, which has suddenly stopped working properly. It has developed a fault whereby the air con works for 10 mins then stops. I’ve had the system serviced and re-gassed, but it still refuses to work beyond 10 mins.

I took it back to garage this morning and they say it could be the compressor which will cost hundreds. Should they not have picked this up during the air can service?