Claiming last month salary after signing the cancellation papers

Good day,

I resigned from my company with a 1-month notice until December 31, 2019.

My company accepted my resignation but had requested me to extend working with them till January 28, 2020. I agreed but had asked my company to pay my end of service till Dec 31, even I'm still working, since I need to settle my loans before going back to my home country.

They told me that my salary for January 1-28 will be given only once I complete my extension. I already signed the visa cancellation and work permit papers even I didn't receive my remaining salary yet. My visa And work permit was already canceled on January 26.

When I followed up for my 28 days salary with HR, they have no response and ignored me. I raised a complaint with the Ministry of labor. We have scheduled a hearing tomorrow Feb 1. What will I do if the employer did not appear on the scheduled hearing?

Thank you!