Mr price accounts system is messed up!definitely closing my account and changing where I shop in future

I was paying my account each month via eft because of the delay apparently I defaulted in payments. I have being receiving emails,smses and phone calls non stop to the full amount .I eventually got so fed up that I paid the account in full only to be told that 700 was still left over which I have no clue of. I phoned the call center and even whatsapped the agent throught their system and they told me that the account was handed over.i tried contacting these ACS people but no one answers nor response to your emails.its frustrating as I need an updated statement and paid up letter as it is affecting my credit score