Easy to open Sim contract, difficult to cancel why?

I took a Sim last year when I opened the account, my Sim is not working in my area. I called at the store 3months back to cancel but I stood there for 45min with no assistance. I then took the numbers and said I will call at home last month I called at home and I was not assisted I was told by the consultant that mrp mobile is busy and she gave me an email address. I emailed them on the 1st of this month and on the 3rd on both instances I got an automated email that I will be contacted within 48hours but I am still waiting for confirmation of my Sim card is canceled or not? Last week I got a call from a lady thanking me for paying well and offering me an upgrade on my mrprice Sim I told her my ordeal and struggle in trying to cancel my Sim, she said she only works with upgrades but she will put a note and I will contacted soon. I still wait. Mr Peter, please assist me in canceling my Mr price Sim I have exhausted all possible ways to cancel it.