I had them come out before I bought my house, they...

I had them come out before I bought my house, they inspected everything and gave me coverage. About a month after moving in I noticed that my A/C was not cooling my house so I had them come out, they said my freon was empty and refilled it for free since they should have caught that during their original inspection. About 2 months later my A/C wasn't working again and when I called in they said they would fix it at no charge because they guaranteed their work. They came out and said its not working because my "A-coil" needed to be cleaned and I did not have a slot for a filter. They then took away my coverage and said they would fix it for $1000 and that my coverage wont return until it gets fixed. Even though they were the ones who approved it for coverage just months before. I ended up hiring a different company to fix my A/C and called service one to get my coverage back. They came back and checked and gave me coverage again. Then I just receive a call from them saying they billed me even though they came here and did nothing at all and they said there will be no charge. Be careful of this company they do not stand by what they say.