Unsuccessful Mandate

To receive money from overseas, one is required to sign a Mandate form for the funds to be deposited into a South African bank account. After using the same account since last year, I got a false unsuccessful Mandate stating that the account details are incorrect. I even went further to send the bank ****firmation letter to Bidvest and follow-ups via email but still nothing has materialised.. My money is stuck for the past five days . I can't use it yet I want to use it tfor back to school expenses. I am frustrated and not sure what else to do in such a situation.