Is it legal? EAD

[tattale]

I had been waiting for an EAD card renewal and had taken some time off work until my new card had been approved. I contacted my work place and told them the situation, and they agreed to wait and let me have unpaid time off. However, as soon as the card was approved (20 days since the expiration of my last card) they said they could no longer keep my job. Could this be considered National Origin discrimination? I don't understand why they would say they would hold my job then once I got the card decided they don't need me any more. I am really frustrated and feel like they just don't want a non citizen working for them. Any advice would be greatly appreciated.

[PraetorianXI]

It is not discriminatory. If they needed to fill your position immediately, then they are entitled to do so.