Give me my money back

Last Sunday I went to PnP and wanted to draw money as well. I got the sms from FNB to say that the money had been deducted from my account but PnP could not give me the money because there was a problem with their computers. I went into the branch and spoken to Dean, the manager who said that he would sort it out for me. This has still not been sorted out, they are not phoning me back. The money is not at PnP and I need this urgently R900,00 is a lot of money for me. PnP have given me a letter and the proof which I have given to them!!!