Demand for 19 year old fee

[Homesky]

CA
In 2002 my wife paid her employment agency a fee to end her contract early. The agency has sent a letter to her old address now demanding payment for underpayment plus interest from 2002. 1670 dollars. I have asked the agency why it took them 19 years to inform my wife she'd underpaid, and I've asked how many years is the alleged debt legally live for. No answers. My wife paid the debt in full in 2002 in her opinion. They are threating her with legal action. Please advise if you think we should pay or if we should ask them any questions etc.

[adjusterjack]

They are full of crap. The statute of limitations for a lawsuit based on breach of a written contract is 4 years. If they are stupid enough to sue your wife can raise the SOL as an affirmative defense and get the lawsuit dismissed. Your wife doesn't need to pay anything or ask any questions just remind them of the SOL and tell them to eff off.