UNATHOURIZED DEBIT ORDER- PAY BACK MY MONEY!

In Nov 2020 I cancelled my contract with Fidelity ADT which was received & confirmed & I was informed that my profile will be cancelled by Dec 31st 2020. Its February and they are STILL debiting me for a cancelled contract. In Jan 2021 I sent an e-mail complaining about the unauthorised debit order & the response was that the issue will be resolve & I will be paid back (I have e-mail conversations). Now Feb 2021 ANOTHER unauthorised debit order and I AM STILL WAITING for the payback of the 1st ******* debit order for Jan 2021. I sent another e-mail & this time, NO RESPONSE!! I WANT MY MONEY BACK & ADT MUST STOP DEBITING ON A NON-EXISTING CONTRACT!