Guest payments

Good day. I have guests that have booked and just arrived. They say that they still have to pay me, that the booking said pay on site? 


My bank details are loaded so not sure what I have done wrong. I also had a 50% cancellation last week and now don't know if I am going to get that money.

Can somebody please help me. I am not sure what I have done wrong and If I have done anything wrong.