Here are a couple of ways to resolve this issue:

1. Ask your IT folks to accept a minimum internalId as a query parameter - you can accept the response, order by internalId, and send the maximum value back as the minimum.
2. Create a restlet as an endpoint - Netsuite's UI tools may enforce pagination. Since this isn't giving you as the user any value, creating a restlet will remove the problem.
3. Submit the search via SuiteQL directly - similar to a restlet, this will let you avoid pagination entirely since it isn't helpful.
4. Do the pagination - here is an example from tim dietrich my read is you should pass a limit of 1000 and and continue to make the call with the offset being a total of results received until the number of results is less than the limit.