Did not fulfill order - very disappointed

Hi,
I searched your website for laptops under £300, and presumably through an error, an Acer Aspire laptop originally costing £349.99 but now costing £0.00 showed up.

Naturally i assumed this was a mistake, but i decided to see how far along the purchase i would get before it was cancelled.
To my surprise, i was able to pay for my order (the postage charge), and i also got an email saying my order had been dispatched.

Naturally i thought "wow, they've actually honoured the order - very good of them".

Shortly after this i received another email soon after when the error had been spotted saying my order had been cancelled.

I was understanding of this development - i had never expected to get as far as i did with the purchase. However, once i'd paid for it and got an email saying it had left the warehouse, surely that order is then complete and should have been honoured?
It was not my fault there was a glitch on your system.

Furthermore, i then received an email asking me to review my order and you hoped i was satisfied. So here i am, giving my honest review.

Thank you.