how to claim compensation

I was worked more than 5 month in a construction company in riyadh. my company suddenly terminated me on March, without giving termination letter or reason and they not allow inside the office. now its 3 month gone still my qiwa contract under same company and my iqama sponsorship also in same company. And also they did not give pending salary for month of Jan and Feb. now i filed a case for pending salary in labour courts. company agreed to pay only pending salary. process is still on going through Najiz platform. I have rights to get compensation for termination according to the contract but i dont have evidence or simple letter to proof that i am terminated by them. if i filed a case then they could easily tell that i was got leave for long time without informing us. what should i do? please help me. ( every week i sent email to them to ask for termination letter but no reply for that mail)