CANCELLATION NIGHTMARE

I have been having issues cancelling RainOne account which is supposed to be super easy as its a month-to-month agreement no contract, I have emailed the team, spoken to their customer care team, even agreed on a final payment amount as they have verified that I have not used their services for 3 months, I have paid the agreed amount and requested confirmation multiple times of the cancellation to no avail, they are now attempting to debit my account a large sum of money which I do not owe and are yet to cancel this account after I successfully made the payment all I require is for them to cancel this accou8nt and collect their router