Hi Jennifer
When you claimed NS ESA you would have been placed in the assessment phase whilst completing your WCA therefore there would have been no overpayment.
You need to get a copy of your assessors report called a UC 85 to see how they awarded you the points. You may want to apply for a MR, also check our guide to see if you might qualify for LCWRA group;
help-for-claimants/esa1 Gary