TuHH calculated my gpa wrong now what to do?. Need help

I'm India and applying to the Bachelor of Science Engeneering Science English taught program in TuHH. But they have calculated my average grade wrong. My grade is 2.1 but they changed it to 3.0. This is totally wrong. Uni-assist and many other universities calculated my gpa 2.1 but TuHH does error. What's the options i have? I have sent them mail regarding the same with my haw hamburg vpd attached. You can say while applying i didn't submitted my vpd along with academic documents since they never asked and now i am not able to change any information in application portal since they changed my status to valid.