Life cover

I was approached by clientele workers when I was passing their desk they explained their their life covers, medical aid etc i was interested I signed up when it was date to deduct they deducted more than what we agreed on when I went back at the mall the lady said it’s a joining fee okay I told her I want to cancel she said she can’t help I went to my bank to reverse they said I should write an email or call clientele I tried that with no clear response or help they continue deduct the money for good 4 months than it’s stopped now I want my money back that was deducted after i have cancelled