Contract breach or not

I received my new contract because i was transferred to a different role. I signed using the acknowledgement system that we have in our company. After 1month of being there, i saw that my allowance was taxable and on the contract it's saying that allowances are non-taxable unlike to my previous salary package. I notified them and waited for their answer and I was advised that they will send me the corrected contract. Then i told them that I already signed the contract so what will happen. They said that they will send me the corrected one and i should accept it. Fear of being fired, i said ok just send me the corrected one and please check my salary coz i'm receiving deductions because of your error. And after that convo, they did not send me the new transfer contract. So i'm working without a contract. Is there anything that i can do with this situation?

whether an allowance is taxable or not is not up to your employers discretion, it is mandated by the BIR.

So upon checking allowances are taxable. So even though i signed a contract saying it's non taxable and they told me they will be sending a corrected contract but as of this moment i'm working without a contrac.