Telkom struggling eight months being charged for data after i cancelled it

I have canceled my line in october 2017 and i cancelled my data where they canceled only my line and is still charging me for the data it is now May 2018 i have phonde so many times and said that the will correct it and i have send do many emails i am now so frustrated and tired I have used so many airtime just to get threw to them I have spoken to people from several departments a specially the account department but getting no where--- does anyone have advice stephenie ********** 425