Income tax return pan does not exist

hi talented people!!

my mom's income is less than 5 lakhs, so she used to file her returns offline..

she filed tds ,ie her money is deducted on 25th feb this year on her pan card no. say ABCDE1234A.

NOW, WHEN SHE ASKED ME TO FILE INCOME TAX RETURN , I CANNOT EVEN REGISTER.

WHEN I TYPE IN THE PAN NO. IT SHOWS PAN DOES NOT EXIST..

NOW I HAVE HER PAN CARD IN MY HAND.. STILL.. I CHECKED HER PAN NUMBER VIA KNOW YOUR PAN AND NOW IT SHOWS HER PAN NUMBER IS SAY  UVWXY4321X, IT IS COMPLETELY CHANGED!!!

I DONT KNOW WHAT TO DO HELP!!!