Avenue Q tickets for tonight can't go!!

xxdeebeexx

I won a pair of Avenue Q tickets in a competition last August. They arrived yesterday just after 10 am for tonights performance at 8.30pm. I have run round in circles to try to get child care but can’t . I have phoned the theatre to see if I could exchange for a later date but since they have not been booked by me I can’t.
I live 45mins away by tube and was wondering if there was a ticket agency that would buy them off me or could I hang about outside to see if anyone wants them.
They have a face value of £50 each………..

It was meant to be a lovely treat but it has caused me to feel very stressed. I would hate to see them go to waste…any ideas?

TIA

Dx