Aramex 4200100

FedEx is represented in Qatar by a nominated Service Contractor: Falcon Express
Telephone: 974 455 41 91

DHL: 4587888

On the other hand and like bleu said, when you have no clue, dial 180 (qtel info number) ask for the company number, call them and get the info. Or do a little search on internet: for example in GOOGLE

Sometimes the responses here may take a while (or not)