Go airport shuttle .com San Antonio, TX Goairportshuttle.com Refused to refund my money when they didnt show up San antonio Texas

They never showed up to take me to the airport. I had to find alternative means after leaving late to catch my plane on time. When I called for a refund I was told I was lying. I have proof that they never called me at my 3pm pick up time. I was out front waiting from 2:30 to 3:30. I tried calling them twice and they didn't answer. I asked to speak with a supervisor and was told they only show up for issues and have no set schedule. I called the corporate office and the San Antonio location and no one will help me. I prepaid $28.50 for a reservation over 24 hours ahead of time and can't get my money back.