ADT Security Services review: being charged for monitoring that my mother never wanted

Can I please get some assistance from someone at adt? My mom is being charged for monitoring that she never wanted. She called the company and asked why she was being billed. I have also called and emailed but have had no resolution. I checked her mail last night and her bill totalled $270 and a cancellation fee of $714? This has been dragging on since may 2018! I want this resolved.