ADT Creditors and Accounts office sloppy service

I joined ADT security in May 2019 as a new client taking over an existing infrastructure installed in a house I bought. The lady from Sales by the name of Yvonne was tasked with signing me up, she offered me a 3 months free subscription verbally on the fone which meant my installments were due to start end of August 2019 and I was happy with that provided the alarm system is fully operational and existing faults are repaired. We agreed on a R350 monthly fee and around September 2019 I started getting calls from the creditors office of ADT that my account is in arrears by 3 months and my monthly payments are R379.50 instead of R350.I queried the arrears and asked to speak to Yvonne who evaded me for a while and eventually when I got her she denied offering me a 3 months free payment plan and I escalated the issue to management who discovered that I had 2 security alarm accounts for the same house and hence the arrears. They tried to resolve it but now and then there's double debits on my account and they barely communicate changes to my account like an increase in monthly installments. I feel that they only care about making money and their customer care service needs attention. They really have caused me unnecessary stress and countless times I have had to reverse unauthorized debits from them,I really can't wait for the contract term to end ,so I can get a better service from another security company.