On Air Tv subscription

I get a call from On Air reminding me to renew my subscription which I declined in our conversation mid January I requested the guy to give me total outstanding before my subscription expires he did and I paid . In June they start sending me sms that I owe them subscription from April I explained to them they said they will deactivate but now they still debit my account for new subscription I keep reversing it with no luck . Last week they call to offer me their new service how do I get new service while they are debiting while I don’t have any contract with them and still claim I owe them