Ignore and block these calls. If you were the subject of a pending civil lawsuit, you'd have received a letter from the attorney for the other party. You'd have a paper trail.
Then, if a case was filed, you'd have received a summons delivered to you by someone licensed to serve process in your locality. You would NOT have first heard about any civil law case from some scammery-scummery debt collector who cold calls you and starts demanding money.
You can check this out yourself by simply going down to the local main civil court and checking the defendants civil list. The court clerks are usually glad to help and are familiar with these kinds of scams.