Shocking Service from Tracker

In November 2014 I cancelled my contract with Tracker because I had bought a new car from Renault Northcliff and my old Renault was a trade-in on my new Renault. The registration of my old car is PYN652GP. Last weekend (Saturday) 22 January I received message after message that there was unauthorised movement on PYN652GP. I called and advised that it was no longer my vehicle. Sunday 23, Monday 24 the SMS messages continued to come through and I called again and again to advise that it was not my vehicle. This morning (01 February) I get yet another message now advising that I must contact the Retentions department and that they will continue to bill me for services!!!! Really!!!<br> Get your department sorted out I DO NOT OWN PYN 652GP and stop sending me SMS messages please.