Bad Service and Very Pathetic Supervisor Response

I have several account that has been handed over to them, cause i resign from my work a year ago. So a couple of mouth ago i got this phone call from differnt people working for the same company, but was only handeling certain accounts. Iong story sort i settle 3from my account two months ago, im still getting sms's on my phone and still receiving phone calls to say i have not paid my account. When i told the consultants I did paid and i have the bank deposit slips they give me a email adress of a supervisor who's name is Sempati Jengece. I email this person like a "million' of times he only respond to my first email saying he send my stuff to queries and they will sort it out. I keep on sending him emails aswell to qeuries no one rep**** and until this day no responds. I do have all my slips all i want is "paid up letters" and for them to keep sending me sms's to say i did not paid. I dont think thats to much to ask. Im so frustrated cause i dont know what to do anymore. Please help