Cancellation nightmare

I have been with Matrix for 4 years and their service was outstanding when I had an accident last year they called me within 2 minutes to check that I am okay and offer assistance. However, I have sold that vehicle and replaced it with a new one, I emailed Matrix requesting cancellation of the old tracker and to have a new one fitted in my new vehicle. The first email was sent at the beginning of August and I have heard nothing, I have sent two subsequent emails and nothing! I have called the call center and been put on hold for more than 30 minutes on each occasion. The service has been absolutely disgusting! I was very excited to be able to have them with me for the tracking service on my new vehicle but after this I will be taking my business elsewhere.