Adt Security
Continue to DR my acc after contract was cancelled

I've cancelled my contract with ADT as I needed assistance with my alarm system and they insisted on charging a call out fee even though I had been with them for 3 years and hardly ever asked them to come out. After cancelling the contract they then want to send out a technician to set the alarm.
To add insult and prove their worth they go on to Debit my account even though i've cancelled my contract. Have the cancellation letter on record and I've now called their call centre on 3 occasions requesting feedback from the first week of this month and still nothing

Pathetic service from ADT!!!