Withdrawal dispute

On the 2nd of September I went to withdraw money from a Cash express ATM, the ATM went of service money reported as withdrawn but there was a writing on the screen which stated that the money has been reversed and that I must contact my bank should it not reflect on my bank account. Today is the 15 and I have still not received my money and when I follow up with them im being told that no one has worked on my case. I have been call them every business day ever since the incident happend.