Bad service. Will discourage anyone from getting this product

Dont even want to give one star. I had a month to month contract. I sold my vehicle on the 16th of April this year and cancelled my contract and emailed it to numerus emails adresses as well as customer care but still today they want to deduct money for my account. Now im being harrest by them about giving notice. I would have understand if it was a 2year contract but this was a month to month contract. How can i pay for something that i dont have anymore.