Expiration of statute of limitations is the time after which you no longer have a legal obligation to pay a debt, and thus the creditor cannot prevail in a legal action to obtain a judgment.
Expiration of SOL does not terminate credit reporting, which is separate. For a collection, the CRA must exclude its reporting no later than 7 years plus 180 days from the DOFD on the OC account.
A debt collector is only permitted to attempt collection on amounts that are specifically authoritzed in the account agreement that created the debt or otherwise permitted by law. See FDCPA 808(1). Review your account agreement with the OC for permitted amounts. Interest is almost always specificed as a permitted in account agreements.
You can send the debt collector a DV request within 30 days to obtain verification of the debt, which should include a request for itemization of the debt, thus permiting you to determine what amounts have been added to the principal, and thus determine whehter they are in fact permitted interest, fees, etc.
