Data Sim cancellation

Cell C sold a data sim Which I cancelled within 7 days .Went to both CellC maponya (unable to help ) and the Glen (consultant there said I should go to midrand head office )no assistance.Call center can’t assist however her contract sim is blocked even though I have existing phone contract and have been a long time contact customer .I am a pensioner this is affecting me And am really disappointed at the level of incompetency from customer service and in-store consultants