I have a collection agency that bought my credit card which was closed in 2005? Amt owed is $12k. Also California Statute of Limitations is 4 yrs? They sent me a letter requesting payment and I wrote that Statute of Limitations is 4 yrs and they never wrote back. But I checked my credit and they still own it.
When the SOL expires it doesn't necessarily make the debt go away. What it means is that if they were to sue you to try and collect the debt, you would have an absolute defense and they would lose. That's probably why you've heard nothing from them.