Bank Guaranteed Cheque

On the 18th of February I went to FNB Fourways to do a bank guaranteed cheque as I was trying to buy a car. I deposited the cheque to the person who was selling the car after depositing the cheque I tried calling the seller he wasnt returning my calls or answering my email, I then suspected it was a **** since the deal was just to good to be true I then went to FNB Westgate Mall to try and cancel the cheque and get my money after standing in the line for a long time I was told it can be only done at Fourways since the cheque was issued by Fourways, I then went to Fourways and I had to ask for the time off since I work for a living, when I got to Fourways I was told that the seller account does look like a ********** account and they cant reverse the cheque after showing them the communication and the contract between me and seller. I was told that they will call me today after not receiving the call today I then call them. Now I am told to go open a case by the police station in order to receive my money. if i was told this information on Friday I would have done everything over the weekend. now do I need to take time off to go to the police station because FNB Fourway didnt give