Ticket sales. How come....?

Right, so I booked train tickets to Barnsley.

I got a reserved seat on the train I asked for from St. Pancras.

I got a non-reserved ticket, for a non-specific train on the day I came back.

I rang to ask what the hell was going on, and they said I had a "flexi-return", which I hadn't asked for. This is based on the time of day I would be travelling being Super Off-Peak. Basically, I am allowed to miss the train I specified, and get the next one. Which goes a different route. And they are thus, not allowed, to reserve me a seat. Despite specifying that I wanted seats reserved.

Bloody trip. I bet I'll be standing all the way there.

I didn't have this trouble going to Manchester.