Mr. pasador your visa is different from ipagaling and aero drive they were under family visit visa which can be extended up to 6 months while yours is a tourist visa which is valid only up to one month. i believed that 3500 Qatar riyals is too much for the expenses that will incur for issuing another tourist visa valid for one month and for the plane tickets ( round trips from Doha to Bahrain, Bahrain to Doha )my advice to you find another travel agency or hotel who can gives you lower price or buy business visa instead of tourist visa because business visa is valid up to 3 months renewable every month without requiring you to exit in Bahrain or in Dubai.