Worst service ever

Fnb has given me a horrible service the worst experience ever I'm stressed and I'm not getting helped. I made a payment from Fnb to Nedbank on the 1st and it was pay and clear but they haven't received the money. When I call I'm told to wait 72 hours every day and pay and clear is supposed to be instant but today is the 3rd the payment was not received the account no is correct the money is out of my account but the person who is supposed to receive it hasn't received yet. Now I'm told they are logging a call for me which will take another 72 hours, what am I supposed to do now as this is my rent money that FNB is not realesing my money this my money not Fnb.