My band teachers are always buzy, and ive tooken it to the shop 3 times & everytime it goes in, i end up paying $45. So my mom gets mad at me, when it never comes back fixed

It wont change from a Bflat to an a-natural. Well it will change but it just sounds like the a.

Dose any one have any idea how i can fix this oboe. if u do it would be a mircle.. Thank you