Refusal to cancel insurance

In Feb of 2015 i sold my house and I immediately contacted Hollards to cancel my insurance. They informed me that i needed a letter from the bank. I then sent this letter about 5 times over 3 months without receiving feedback, not even once. I have spent over R 1500 in airtime in trying to cancel my policy. I have spoken to about 10 different people including supervisors. I have had conference calls between myself the bank and hollard and still nothing happens. They in total owe me over R 2000 in instalments over a 9 month period. I can supply numerous reference numbers and my ID number on request. But in all my life i have never experienced such *********** ***** in my life every single consultant and supervisors have made empty promises to assist and have my money refunded and not even one single person has actually phoned me back as was promised by them all. I have had it with those absolutely useless company. Please hello peter assist me in this matter