Terrible service

Last year November I requested ADT to cancel my subscription, however the request was not honoured, ADT kept billing me, but I wasn’t paying at the time due to my request to cancel, again in Feb I requested a follow up on the cancellation, still no response from ADT but they were still billing me and reporting to the credit bureau, recently someone from their legal team Melanie Mulder messaged me for collection, I forwarded her the original cancellation emails and she was kimd enough to cancel for me and close the account, again this month I received billing from ADT after the account was closed. I then spoke to the credit bureau to remove the negative judgements from my credit profile, they responded by saying they need a letter from ADT vonfirming closure of the account, I then emailed Melanie Mulder as well as the Customer services to request the letter indicating my account was closed last year November….to date no response from ADT. So quick to add negative credit records but to correct them they become slow..