Cancelled the service and waiting for refund!

I sent an email to cancel my service in December 2022. After a few calls from ADT to try and retain me as a client I decided to cancel anyway. Having been a client for several years, my debit order was setup as an annual payment in advance, which went off last December. I have been trying to get a refund from ADT since the end of January and nothing yet. One reason provided was that refund to my bank was returned, the same bank and account from which debit orders have been deducted for years. The most recent reply was that the refund was processed a week ago. Still nothing in my account. I have been sending an email weekly and also called a few times now. Very disgusted by this.