Cartrack incompetence

Since 16 April 2016, I have been struggling to get Cartrack to de -install and re-install a tracking device. After 7 e-mails and 8 calls to rectify the issue, I gave notice to cancel my contract with Cartrack due to non-delivery and therefor breach of contract. Up to today, the issue has not been resolved , but Cartrack keeps putting through a monthly debit order although there is no vehicle being tracked as it was never installed. Can someone in management please contact me to finalise the cancellation of the contract. Absolute incompetence!