I dont owe you EDGARS RCS, Close the account with immediate effect

I have received a string of harassing calls, emails and sms recently from Edgars RCS. I have settled my count a while ago but they now claim I have a insurance and other charges which are not related to purchases. Im told I owe different figures of amount each time the communicate via the above. I told them to close the account but they insist that I owe them but cannot prove that I did a purchase or have a funeral policy with them. RCS/Edgars prove yourself that I did purchase or have a funeral cover. My account has been dormant since January 2020 with -R100 and and in May I did a purchase of R499 and in October I paid R500 plus change to close the account. AND NOW THEY CLAIM I OWE THEM!!! Acc No: ***