Frustration with MRP Mobile and Blake and Associates

Good Day, I had a contract with MRP Mobile which ended in 2017. Nowhere was it ever made clear when the contract was given to me that when the 2 year period is over will I have to send written consent to ensure that the contract gets terminated. Imagine my surprise when in 2018 I started getting phone calls demanding payments for premiums missed. I still asked what type of customer service is this to only call a customer after over 6 months to remind them of missed premiums? I payed monies as was conveyed to me on several occasions and i even send a request to ensure that the contract is cancelled as I was not getting the service I initially was promised. I ended up getting calls from Blake and Associates whom I also sent the proof of payments to. I am still getting calls from both Mrp Mobile and Blake and associates and now the amount outstanding is over R1000. Please assist to resolve this as i feel it dragged on too long.