yes you can serve complain in the labor dept. but i think, this is only a wasting of time. because from what i know in the Qatar Labor Law, salary scheming/bracketing was not mentioned and they did not required it.

Meaning even you are Engineer, Professional, experienced worker or licensed practitioner you can still receive a low and unfair salary offer.

Offering a good salary or salary adjustment is always depends to your company's discretion...and also it will depend to your own decision if you will accept their offer or not...if your are satisfied to their offer or not...

and not necessarily that once you have transferred in a higher position you can expect for salary adjustment too...increment or salary adjustment will again depend to your company's mood if they want to give you or not...

and even you file a complain in Labor dept. they will just ignore it because there is no ground of uncompliance to be considered.