Bad service given

I needed unlimited data for online course iI was doing. My current data from service provider would not have been sufficient. I contacted Rain paid R479 online. At no time did they mention I need to cancel ,as they claim no contracts. End of October 21 Rain debited my account without my permission. I contacted them then paid the outstanding amount and many emails and phone xalls to ensure this had now been cancelled. 1st of December 21 they tried to debit my account again. Saying they billing in arreas. Yet in am not using any of there data since 17th of October 21 and I gave them a month's cancellation notice. So disgusted with pathetic and underhanded service given