Termination on the spot without ever being verbally or written warning.?

I was terminated on the spot due to a procedure that I did by editing my sched. Not to my benefit only when I was there. Never was I told after yrs. of doing this (I was a supervisor) was that it was a falsification of records. however when they terminated me they did not discuss when I could recieve my final pay or my PTO hrs payable at termination. This has never came up with our company before & I feel that sice I have had some illness this was a loop hole that allowed my termination