Approved at 1st attempt and rejected at 2nd why?

My query is regarding my project submission. As have submitted it yesterday and i got only 28 marks out of 40 with remark that i have missed some things in TaskA and B. After that i re-submitted the project on same day. And my project got rejected how? When it was approved at first why it is rejected, as i only changed some things from PPT and rest is same still. Please help me with this, as there is no means to contact your support i have been calling from last 2 hours and no response. I want to know why my same project got marks in the 1st attempt got rejected in 2nd And after i discussed it on chat they reply me with same remark i got on rejected status that this is missing not complete. how is it possible that it was complete in 1st attempt and now its not