First Bank of Delaware I am being charged an amount that is way over any credit line they would give me. Wilmington Delaware

Asking to settle could waive your rights - please talk to a Delaware attorney or look this up yourself.

The Statute of Limitations [SOL] precludes law suits after a specific number of years that is longer for breach of contract than most but it is not forever, and it is shorter (in Nevada) when there is no written agreement.

Many of these statutes are tolled (start over) when you enter into negotiations.   I believe that is the real purpose of collection calls and I do not speak with any of them.   I have had calls where the address or my name, 10 years after my divorce, gives them away and otherwise one would never know they were trolling for an alleged debt long extinguished by statute.   In your sitch, it might be a company that took over for another card, or they might have the wrong person altogether.

It would be safer to investigate by getting a copy of your credit report than to speak with the collector.   You've done OK telling them you know nothing about it.   I often add to that - I know nothing of this if you think I owe you money than sue me.   Companies use credit score to collect "debts" without the scrutiny of a court.  

Partial payments also toll the statute.   I never make them until I've decided that the debt is legit and I intend to pay in full.   Making a payment to appease a bill collector just waives your rights under the SOL.

Good luck.

I've been so meaning to write about this - thanks for the motivation!

Nancy