Ni hao laoshi, ni zui jin hao ma?

I recently try to get my mandarin level up and i also studied in a local school. But unfortunately i did three times mistake in examination for the brown belt and now the system will not allow me to pass to the black belt even when i answer all the questions correct. Is their anything i can do to get the black belt award, it has been my dream since i started learning to reach the black belt and i didn’t know the if i fail three times i will be blocked out of the system. Please if their is anything we can do let me know. Thunk you for your time..