Bad service ever

Good day

I have a serious issue with ADT in 2018 i have install there security system at my place in order to increase the security but guess what instead of them to supply me with the security services the just saw a cash *** out of me cause there system never worked for me since 2018 i have tried to contact them without any luck every month the kept on debting my account but without out even rendering any security services there system was always off and i never even a single day saw them patrolling when i call them there keep on saying there will send a technician till to date then i decided to stop paying my monthly premium since i wasn't getting the service and the called me regarding the monthly premium since there are very fast when it come to that one and i explain to them the reason i have stopped paying hopping the will assist me but guess what instead of them to resolve the matter the handed me to some legal debt collection company who keep on call me day and night and when i explain to them why i stopped paying my monthly premium don't know what to even say but the continues to call me on daily basis so am asking myself why should i pay for something that i didn't get