There are several Haj & Umrah travel agents in Doha. You can get their contact details through Google. The one I knew has shifted his office and I am unaware of his new contact details. You must act immediately and take their advice when to apply. This is because during Ramadan, there is a rush for Umrah visas and shorter working hours delay things a bit. During normal days, it usually takes a week to get an Umrah visa issued. The visa is valid for just one month from the date of issue for travel. The last time I went for Umrah, I paid QR 250 to the agent to have one issued.