I was charged with fraud. As I did cash advances at work when people paid with cash and instead of going to the bank myself to get cah for me I took the cash but paid their account by debit or mc how much trouble am I in?

Lets say you are going to need a lawyer... and they will explain it better depending on the charges filed.

Yes, you are in serious trouble, don't say a word, don't confess to anything and get an attorney

This could be in the 1000's of dollars

Also don't you realise how much money the store lost each time you did that ?

If you did lets say 500 dollars they have to pay the credit card company a process fee. Of from 1.5 to 3 percent. So they may have loss at least 15 dollars on every 500 you did, plus batch fee plus other fees when they get paid from the atm card or credit card.

Also it takes the company 3 to 4 days to get the money from a credit card machine so they loss use of that money for many days. (loss of interest)

Depending on how much money there was done this way, and how many days this was done, you could end up owing them a lot of money besides fines.