First National Bank inaction on refund

A hotel in Cape Town where a stayed, debited my FNB Visa account with a pre-authorised amount of R3000 to cover any incidental expenses. When I checked out on 25 September, they cancelled this pre-authorisation and gave me the credit card slip on which it was indicated that the amount had been cancelled. It is now 2 weeks later and my credit card account has still not been credited by FNB. When I made enquiries at their authorisation department I was told it could take 5 to 10 working days to credit my account. Ten working days have now passed, and FNB is still ********ly holding on to my R3000 with no logical explanation.