Any right to cancel purchase of tickets to an event?

I bought some tickets last night for an event on Saturday (email delivery of tickets) via See Tickets.

I completely forgot I was already doing something that night and can't go - do I have any right to cancel the purchase?

Its not the end of the world but I'd rather not throw £20 away.

The See Tickets T&C's seem to imply I can't
(http://www.seetickets.com/Content/Terms-and-Conditions)

but I wondered if the EU Consumer Rights Directive had any bearing which states -

Goods or services bought "at a distance" for items bought online, via mail order or over the phone, once you've received goods you now have 14 calendar days from the day after receipt of goods or completion of a contract to ask to cancel the contract and get a refund. Previously this was seven working days.

http://www.moneysavingexpert.com/news/shopping/2014/06/shopping-online-or-by-phone-your-consumer-rights-are-now-boostedHowever, the other MSE page on cancellation rights includes as an exclusion "Accommodation/transport/leisure services purchased for a particular time frame"

Would this count as a leisure service? I have no idea.
http://www.moneysavingexpert.com/shopping/consumer-rights-refunds-exchange?_ga=1.253601737.1762979139.1406631458#web

Any views welcomed