Any time revision?

I did an expert witness report about 18 months ago in a case where there was an alleged fraudulent claim for IS, CA and IB.  I pointed out that the DWP was treating properties owned as capital for IS and a business generating earnings for CA and IB; which was somewhat contradictory.  Following some negotiations, which I wasn’t involved in, the IS overpayment was accepted with a guilty plea and all went quiet.  Now a civil debt recovery has popped up for the CA and IB that fell outside the criminal case. The IB ranges from 1994 to 2012 and the CA from 2012 to 2016.

I have no idea where the best place is to start with this.