I'd ring them again and demand to speak to someone higher up as there is NO excuse for this not to be sorted there and then over the phone. I think the sub thing is a typo though as the CS agent probably copied and pasted it from a template.
I think I did hear they have to cancel the original order though and submit a new one. You might want to mention the original $250 pre-order price though, incase they submit an order for the higher pre-order price! The bright side is you have over 3 months to sort it out and I'm sure things will get sorted eventually