Should i be paid my commission bonus for the prior month after i have been fired?

• the moving company
• link building company
• paid loans

I was working for a company since September 2013 and i got fired on November 11th 2013. I earned a commission bonus for the month of October but 1 week before i got my bonus check for the prior month, they fired me. should i still be paid my bonus? they are trying not to give it to me and i think its Washington law that they have to.

Should i be paid my commission bonus for the prior month after i have been fired?