However as a result of the shows being cancelled, the event organisers from Wembley Stadium have confirmmed refunds will be given to customers:
“Following the announcement of the cancellation of the two Foo Fighters shows at Wembley Stadium, London the event organisers can confirm a refund of the ticket price and booking fee will be made to the original ticket purchaser beginning Wednesday 24th June 2015 at 9am.
Your ticket outlet will automatically handle this refund transaction to your credit or debit card on this date.
In the event of any issues arising related to your refund please contact the outlet you purchased from directly after the listed date for refund.“
More information can be found here.