Hello,
For some reason, I swapped accounts from one server to another. Now, it doesnt go to the address even though I have control panel access and my files.

I ran a dns report, and it brought me to the correct namevservers, but no A records, mail servers, etc.

I have to do this for 280 accounts.... how do I fix?

If you provide more information on how you did the transfers may help, as much information as possible. Was it through WHM or by some other method?? You may find an answer to your question then but what you have given is very vague

Is the nameserver up and running? Happens on 1 account or all?

Check if there is record for the particular domain in /var/named and /etc/named.conf

When I transferred mine from ANz dedicated to ServInt's VPS, none of the accounts worked.

When I called ServInt, the tech immediately told me it was a permissions problem and he fixed it in about 5 minutes.

Perhaps if you give us one of that 280 domains we can advice better.