Pic and pay store card

I was approached by an assistant in p and pay clothing to get a limit on my card for R10000 to buy whatever I wanted anywhere - I went thru the process and received the 10 000 limit - she said I needed to use the card to activate it so I bought air time - I was never told I had to pay a service and insurance fee regardless of using the card or not - when I realised in December I asked them to cancel the facility and send me a settlement amount on 6 December 24 which I duly paid and from that I still have an ongoing query about this I am getting harassed by the collections at rcs by phone and emails eventually lorenzo sammuls tried to assist me and it is still a problem and how do I sort this out as I’m fed up the amount is R146 odd its cost them more than that just in phone calls