Adding to the story, just to let people know Thalys still don't refund as they should...

Booked an OPTIWAY (changeable and 50% refundable) Paris to Brussels. Called a day before the return to change, was advised it couldn't be done but he noted on the system the ticket was cancelled. When I returned to France I was to ask for the refund there.

Got to Gare du Nord, asked for the refund at the Thalys desk - "I've never heard of that before" said the woman behind the counter, who really tried to be helpful.

Just called up the same Belgian number on my confirmation email, and they gave me a number in France to call - 08 92 35 35 36. The guy told me no, as I hadn't called THEM to cancel (and how would I have known otherwise?) it's too late. I will have to write an email explaining the situation.

So... let's just say life is too short. Sometimes we pay for lessons - my lesson is, NEVER book a refundable ticket with Thalys on the offchance your travel changes. Book the cheapest possible, because if you don't use it you'll just lose less money. But at least you'll know that up front.

big-time