BSNL Broadband — problem with updating of plan B 250 TO H500C

My profile is being updated to H500C plan on 2 jan which i had seen on my profile, so i make unlimited download from 02:00 to 08:00 but its was actually been updated to 7 jan .. so that i make 6000mb downlods which was TOO much...as told by the officers that its was bangalore servers problem this is clearly not my fault .. plz look into this matter...

telephone no. [protected]