HELP HELP HELP

Okay I am still searching for the answers of the "Mysterious Aircon" problem. They have done a full computer check on the car and it shows no problem areas at all. Well , some might say this is good. However, the air con still cuts in and out. We have replaced the compressor, but it has not fixed the problem. Is there some one some where who has had the same problem, or is there a contact for emailing the manufacturers?
Getting desperate, hot summer is on the way.
JoAnn