Woolworths account with R0 credit limit

I've been trying to get hold of woolworths but they don't reply or get back to me. I've been sending countless emails to them but the reply I only get is that they have forwarded my query to the relevant department and it's been months since my query has been forwarded to the relevant department. Woolworths shows a balance on my account while it has been settled with R0 balance and I've forwarded my paid up letter and to my surprise my credit limit is now R0, what is this Mara? I've been using cash to purchase while I'm having an account, if they don't want they must close the account and start afresh to apply because this account appears on my credit report with R0 balance but to them I'm still owing. Hope this will be corrected and they must give me back my credit limit if not then they must close the account. How can you use an account with R0 credit limit while on my credit report it shows R4800 credit limit.