I called in sick to work on the Friday of last week so I missed 8 hours of work! My employer then informed me on the Monday when I had returned that he had already submitted payroll for the month on the 9th of December(even though we don’t get paid until new year) so I have to make up those extra hours. Is this normal protocol? I am only a Christmas temp so I finish up on the 3rd of January and he is asking me to complete the hours before December is over which seems impossible as I only have 3 days off over Christmas to be with family
If they submitted their payroll even before you actually did the work, that is their problem and depending on jurisdiction even borderline illegal and/or tax fraud.
However, it's not your place to complain or rub it in if you want to stay on friendly terms with them. You can offer to pay them back if they accidentally overpay you. You can offer to work additional hours if you feel fit for it, even if it's not the full 8 in the end. But they cannot force you to do anything else.
Depending on your location, especially in many US states, they may however fire you for "no reason" or any other reason ("didn't meet our spontaneous scheduling demands" is as good as any other reason if you are in a country with non-existant worker protection laws). That sucks. But assuming you live in a democracy, it's up to you to change that at a voting booth.