Frustrated mix telematics client

My MX3 unit stopped working more than a month ago, I’ve contacted mix telematics and sent emails to have this device rectified without any success. The customer service line rings the entire day unanswered and the two times I managed to speak to a consultant, they took my details so the right department can contact me back ...a month later, I’m sitting with a unsecured vehicle with unanswered calls to the service provider. At this point I’m just going to tell the bank to block their transactions maybe if my account is in arrears they’ll call me back.