USELESS ADT SECURITY

After ending my contract and cancelling successfully with a letter, they still wanted a further 30 days notice, for which they deducted a premium for Sept 2020. October they again deducted a monthly fee which my bank reversed. Begin Nov they again deducted the monthly fee which my bank reversed and 2 days later they again deducted the same amount. I have had no joy with phone calls as no one gets back with a solution, The MOST *********** company ever. Do not use them as they are useless!