As per department of NTA's schedule, the OMR scan (NEET UG)

As per department of NTA’s schedule, the OMR scan (NEET UG) of this year was released on the official website on 05-10-2020. I noticed that the bubbled answers in the scan issued greatly differs from my originally marked answers. I could have proceeded through key challenge option if there is change in two or three questions, but there are more than 100 answers are differing from what I actually marked. So, I am not in a position to apply for key challenge. Many unattended questions also got marked in the OMR scan Copy, and many attended questions not marked in the OMR scan Copy.
The actual expected marks of mine as per NTA answer key and what I originally marked in the OMR sheet should be around 560marks, but as per the downloaded OMR sheet it comes only around 260 marks.
In the final rank card also I got only 260 marks
There is a huge difference in marks which could seriously affect my future.
This is my daughter’s case.
I already sent mail to nta, but there is no response.
I like to know if anyone is facing this type of issue
I request anyone to gaid me for proceeding further in this case