Closed account not closed

ABSA has not been my banking provider for 8 years, but at the start of the year I made a mistake in paying, what was supposed to be, a closed account (closed at the end of 2006). Still don't have my money back. If ABSA closed the account as they should have I would have only waited two days to get my money back. When going to ABSA, the support or help I got was of no help at all and they couldn't tell me why the account was still open.