Interest Charges On A Closed Account

I'm writing this review, because I'm so angry. Had a staff account with Edgars, which was closed in 2019 when I left in August. My account was paid up, with a credit balance of R65. Which I utilised, via the ThankU app to buy airtime. Not do long ago, I decided to get myself a credit report. Boom there's Edgars, saying I owe them R142 something, now sitting on R200 and something. What the hell should we do now, because I won't allow Nimble to mess up my credit profile. Hell will break loose, because I'll sue the companies pants off. This is totally obsurd, and makes me so angry. Please fix the mess you guys made, because I'm not going to pay any cent. You money *******, think you can make quick bucks with people. I'm not gonna let this one slide, till you sort it out.