Can't get anything right

Last year I need to have a tracking device fitted in my car. I called Altech Netstar. First they took time to install the unit, I had to follow up multiple times. The installers installed the unit but it wasn't working. I followed up with Yvonne and she sent me the certificate nonetheless. I got a call from the installers to install the unit again. It was a different guy this time around. He left and told me I would receive the details that the unit was installed and working but I didn't. I tried calling (waiting >10 minutes each time) to test the unit and I spoke to Thabo who told me I had to go start the car to activate the unit. He said I would receive an sms, which I received reading \We are unable to verify the information you have supp****. Please contact Altech Netstar for assistance."I informed Yvonne and they didn't help. The next thing I received were threats from debt collectors when I had supp**** my banking details for debit orders. No one from Altech had bothered to follow up on my complaints and no one informed me that they were unable to debit my account until these sharks called me. How is this company still in existence is mind boggling."""