Pathetic customer service

Yesterday the 27th I went to total sports Savannah mall in polokwane to pay my account and the cashier accidentally swiped 8400 rand from my cheque account instead of 840 rand .I informed her immediately but I was told it can take up to 7 days for my refund. I can't even pay my life insurance,my debit orders etc because part of that money was for my debits.i am even going to pay for unpaid debit orders..I am very saddened and heart broken by this.how can a company as big as tfg do not have better measures on crisis like this..I am so sad and once my account is settled iam out of the group for goid