Illegal dismisal

I was asked by my former Dean and chairperson to apply for a teaching position in our school which i did, then i was called by the HR for a test, an interview and a Teaching demo which i passed and was asked to undergo medical exam which came out pretty well. Then the HR asked me to submit employment documents then i started teaching as per instructions by our Dean and then until about 1 week of teaching i was notified by my chairperson that the VP for academic affairs didnt sign my contract and endorsement because she claims that she knows me and doesn't want me to teach in our university because she doesnt think that i am capable of teaching... I actually do know her because she was my dean before i decided to shift to my degree... I actually dont have the best credentials but i know my capabilities I havent signed any contract but my application went through the right process and like what i have said i already met my students and started teaching until i was called about the matter... Is there any legal matters that i can do with this? I felt that she got personal with me and didnt act professionally... Thanks! I hope i can get some help here... Our university has been existing for over a century now....