Woolworths nightmare

I'm very shocked I payed up my silver Woolworths Visa credit card which I first paid via debit review Key debt 2 freedom. I opted out around 2016 but I have been getting calls that I owe R1103. 00 and the debt review said that I opted out this year last month. All is a lie after I opted out I was paying at Absa. I'm not willing to pay something I don't owe I paid up all my accounts. Can woolworths stop harassing me.