Cellc stop deducting my MONEY and close your account like you confirmed you did

I had a 12 months data contract with Celc , end of may i requested celc to cancel my contract, and they told my to pay for the router as well as the invoice of that month, which i payed for the router and provided them with proof of payment and they deducted for the invoice end of the month as per our agreement because i was told that invoice was out already when i requested the contract to be cancelled. i payed cellc every cent that they requested from me, and now end of June they Deducted the money whilst i received an email from them saying that my account is cancelled, the question is for what ? secondly i recently did my credit check and i found that the cellc contract is active, i need that to be cancelled and cellc to stop deducting into my account because i am no longer with them, and cancel the account.