Very disappointed in ADT

I have been a customer of ADT and its predecessor in Port Elizabeth for more than one home and business since 1978. Having recently sold one of my houses, I enquired about how to cancel my service. Upon my First enquiry around 30 Oct 2018, I was informed that I must wait for registration in the new owners name. Registration was effected on 13 Dec 2018 and I am now informed for the very first time that I need to give 1 month notice. I am very disappointed, my faith and trust in ADT has been lost. ADT is just being exploitative in trying to get one more month of subscription from me for a service that is not required. I would not recommend ADT to anyone.