Business model that penalises loyal customers

I have been a customer of ADT for over 20 years and have just found out that I'm paying way over double and even over triple of the monthly fees of other customers in my suburb. When I asked ADT for an explanation I was told that because I have a longstanding contract with them my fees have risen and compounded year on year. So in other words their business model is to penalise loyal customers to the point of ripping them off. Even though I phoned and asked for a proper explanation three times I have so far not received any. People need to be warned about this business model which makes it more beneficial for their customers to cancel their policy year on year and take out a new contract. My monthly fees are 978.00!!!!!...the other two amounts paid by clients with exactly the same size properties in my suburb are 450.00 and 290.00 respectively. Be warned and check fee differences in your area.