A First Response HVAC

This company was referred to me by my home warranty company. I moved into our house at the beginning of July. On July 29^th I came home after work and the central air was off — circuit breaker was tripped. I reset it, started the AC unit, and it tripped again. Breaker was pulling over 50 amps at the panel.
I called AHS — They set me up with this company. They went out to my house, and that was it. I never received a call from them, or anything for that matter. Called and left them 5 messages, with no call back.
Called AHS and they said that A-​1^st stated that the central air was never working, and definitely not working prior to the home warranty date. The unit was running fine, (even have the home inspection stating so, which is why we purchased the home!!!). Apparently this company does not want to complete the work, does not return phone calls, and evidently is unethical and deceiving, as they lied to the home warranty company.