Ya one more thing, company can terminate contract( limited or unlimited) based on Article 61 of Qatar Labor Law which says:-

Article (61)
The employer may dismiss the worker without notice and without payment of the end of service gratuity in the following instances
1. If the worker assumes a false identity or nationality or submits false certificates or documents.
2. If the worker commits an act which causes gross financial loss to the employer provided that the employer shall notify the Department of the incident within twenty four hours from the time of his being aware thereof.
3. If the worker violates more than once the written instructions of the employer concerning the safety of the workers and the establishment despite his being notified in writing of the violation provided that these instructions shall be written and posted up in a conspicuous place.
4. If the worker fails more than once to carry out his essential duties under the service contract or this law despite his having been notified in writing thereof.
5. If the worker discloses the secrets of the establishment where he is employed.
6. If the worker is found during the working hours in a state of drunkenness or under the influence of a drug.
7. If the worker commits an assault on the person of the employer, the manager or one of his supervisors in the work during the work or by reason thereof.
8. If the worker repeats his assault on his colleagues in work despite his being warned in writing thereof.
9. If the worker absents himself from work without legitimate cause for more than seven consecutive days or fifteen days in one year.
10. If the worker has been finally sentenced for a crime involving immorality or dishonesty.

But again I would insist, you guys have full right to ask for explanation of termination and based on which article of law have they been terminated. Even in case of Article 61(above), they cannot process such termination without following proper company internal investigation procedure, a copy of which should be given to employee and company has to send one copy to Ministry of Labor. If they have not followed this process, then article 61 cannot be applied on employee and will be deemed null and void. I strongly suggest you approach Ministry of Labor and seek their assistance.