Hello aspirant

Please don't be panic .

If your admit card is without surname then too you were allowed to seat for neet .

At the time of counseling,  they may asl you reason for missing surname in admit card but it won't be a big issue. You must carry all other original documents with you at the time of counseling so that they can confirm your identity.

Till then keep on trying neet help line desk. Yes it might be busy because of the heavy traffic on it .

After three four days , the help  line desk will work smoothly then you may mention your problem.