Stu, the US airline industry has shamelessly used 9/11 (which was enabled by their massive lobbying effort to close the US sky marshal program in the 80's, while the rest of the world continued with armed marshals) as a money-maker. Non-ttransferable and non-refundable tickets, or tickets that are "credited" but then expire within a year, are pure money
makers with no other purpose.
IIRC Silver Air is a very new company and their ticket agent may have simply been mistrained or misinformed, a written complaint to their corporate hq might get a refund.
The airline "industry" pretty much follows the same employment
guidelines as the burger chains, these days.