No impressed SA payment Exchange not answering phones

today i find a debt order on my account for R99.99 from Mzansi4u (who's details i am unable to locate). the payment reference came from SA Payment exchange with the number ********** 750. I tried calling this number and kept getting a recording indicating that they only start operating from 09:00. called after 9am and still no one is answering. All i want is to find out where you got my banking details from cause i did not sign up for anything with Mzanzi4U. I would like this debt order cancelled with immediate effect.