You have the right to claim your gratuity according to Qatar Labour law. If they just terminated your contract verbally and they ddidnt gave you notice thats another case. You can go to the labour law in C-ring road and ask for advice and if you want to complain you will go to Labour Dept at Industrial area. St. No. 13. They will help you there. But as far as the same situation with you, you have the right to be compensated as per your contract. Hope things will be fine for you too.

Goodluck