I recently started working in another city full time, I was going to relocate, due to errors relating to home purchase I have stayed working in my home city, I did decide to go per diem at the other position and without my knowledge I was terminated from their system. I now must re-pay the relocation bonus and sign on bonus, before taxes total of 7500.00. They want all money and from what I understand since this occurred this year they can receive that tax from govt. Unsure how to proceed with this. Also unsure if the termination was legal or not, I had no discrepancies and was not put under any action plans for corrective action. Their handbook states there is a three step process but since I went from full to per diem not sure where I stand. Appreciate any input.

If your state is a right to work state, if you did not have a contract, if you were not part of a union, they may fire you at any time without notice if they so desire. While they may have a policy, I am sure there is a note in the pocliy that this does not involve a contract agreement.

Also since you were a newer employee, I would assume they have a policy for firing someone under 90 days of employement.

Also if you asked to change to a per diem status, perhaps they did not want a per diem employee but a full time one.

Some states have emploment at will laws but if you have a contract or something binding then it should be more difficult for them to let you go. NLSA - Getting Fired

You can be fired for just about any reason (or no reason) at all. The normal rule in Pennsylvania (and some other states) is "employment-at-will". That means that most of us can be fired for just about any reason. Most of us can be fired because our boss doesn't like us, or because it is raining outside. However, if you have an employment contract, your employer may be able to fire you only for specific reasons. For instance, government employees and union employees can usually be fired only "for cause". If you have an employment contract, you must examine it closely to determine if it limits the reasons for which you can be fired.