Expenive, and do not back up their work

My initial call out for a service was responded to very promptly. After the service, we discovered a few problems, as the aircon made a nasty noise if run for a while, and wasn't really getting cold despite the re-gas. The office promised to send a team back to my house, but they never pitched. I followed up numerous times, and was eventually told that they wouldn't come to my house for the complaints. Their attitude being that these must have been pre-existing issues. And that's it - they don't reply to emails, and the reception puts the phone down on me. They were also very expensive, so I really recommend you stay away from this company.