ADT CANCELLATION TROUBLE

I called ADT to cancel my alarm system and i was told to send an email with the request. I sent a cancellation request to ADT beginning of Mar 2018 for cancellation from April onwards. Email acknowledged but was nothing was done snd I was debited each month. I kept calling each month to try to cancel and they would promise that cancellation was done but i still get debited. In June 21st I spoke to Christopher Bosch who even sent an email confirming the cancellation and refund to be paid in 14 days. I had to call again on 12 Jul to find out when my refund will reflect and still no answers. On the 13 Jul I was told that my refund has been processed but it will only be for 3 months not 4 because clearly they decided to ignore my request then they only cancelled from May and not April. Who knows if i will even get that refund for 3 months