Employee's rights against employer for breaching employment contact verbal promises under WA state law

Upon hire I entered into an at will (+) an oral contract with "T" for long term employment ~ for no less than 2+ years and after 2 years I would then possibly take over "T" 's position for upper management/supervisor of nursing staff.



BACKGROUND INFO:
"C" took "R's" position who was gone on sick leave and I was hired for "C's" position.

"R" returned from sick leave and resumed her position - resulting in "C" without a position.

I was approached by "T" who stated, "I'm sorry but I have to let you go because "C" wants her previous position now that "R" has returned from sick leave.

I was told I was an excellent employee, I had done a wonderful job but there were no other available positions.
I was also told that I was eligible for re-hire.
I received zero notice and the termination was immediate.
I asked for and received a letter of recommendation (glowing).



Given the facts as I view them - shouldn't "C" be the be the odd man out with myself retaining the position in which I was hired ?

Is this legal ?
Do I have any recourse ?
Can I get my job back ?
How ?
Need I fear from retaliation, as I have a medical license to consider ?

Can you help ?



Thank you,
T