Contarct Termination

MTN makes it very difficult to exist a contract. I fully paid my device and opted to end the contract via email, it has been over 12 months and I am still paying for Airtime Subs that I do not use as I have been out of the country for 2 years now. I have contacted them via email, whatsapp and sms with no response. This is ********* behaviour on their part. Extremely disappointed. Please end my contract MTN. Please.