If you're not particularly enjoying the content covered in the course, then by all means change to something you'd enjoy more. Geography's not a compulsory course; it's an elective. The purpose of your elective subjects (i.e. pretty much everything bar English and Maths) is to allow yourself to choose the subjects you're best at and which you enjoy the most.
Bottom line: if you find geo 'boring', then get the hell out of there. You do better in the courses you enjoy anyway.