Most uselesa cellphone provider

Ok this complaint ia frim last year Sep that i am trying to cancel the most useless celphone contract. You did help and Porche called me back garanteed the contract will be cancelled and i owe them zero nothing. Guess what today again a call why disnt i oay R160 something. O my gosh ive liat it, yes the cintract is cancelled but i still iwe them 160 odd. Well ive paid now 170 to get rid of this useless privider. Could they give me a letter that thisnis now done and i will not get another call in 2 months wanting more money. I had it now with this network i want it in writing as their word is useless