Settled contract but still being debited

I requested a contract cancellation and got sent the quotes to settle the contracts. I paid the amounts immediately to settle both accounts and have still not received a response or acknowledgment. When I phone in I am advise that I will still be debited this month for my contacts even though I've settled them 7 days ago and the debit is only going off on my next debit date? I have paid to settle the Subscription, Equipment and the contract subsidy balances of both contracts so please explain how I am still due debit orders?