2x return coach tickets from glasgow to birmingham +

I was planning a trip to Birmingham but cant go now. I have 2 adult return tickets leaving Buchanan bus station at 23.00 on Friday 10th August and travelling through the night to arrive in Birmingham around 06.45. Then leaving Birmingham on Sunday 12th August at 11.00, arriving back in Glasgow around 17.40. Havent received the tickets in the post yet but whenever i do i can post 1st class or deliver to an address within reason if the wont be received in the post on time. Thanks for looking.