Malicious harassment over already paid account

I am one of many monthly account paying customers who is maliciously harassed every day by Edgars callers to “settle” the monthly payment that I have already made. When I tell them I’ve already made payment they do not check it on their system, they just cut the line and then phone me about 2 extra times that day to harass me only to cut the line again every time? I have paid numerous “collection” fees due to their mismanagement and Edgars have “handed” me over on many occasions due to there lack of competence when keeping records of payment. What is your deal Edgars? Why are you so poor at your customer service and how do you think you can get away with treating all of your paying customers this badly! Extremely unsatisfied with your service and can’t wait to close this account - if I can even do that since your service is so awful.