Glasgow to London return ticket in mega bus +

Hi there, I have bought a return ticket from Glasgow to london and return but I got my trip cancelled. Please write to me back if you need it, the journey is scheduled as Glasgow to london: 14/5/12 at 23:00 hours which reaches london at 7:00 London to Glasgow: 24/5/12 at 23:45 which reaches at 7 to Glasgow. I paid 31£ but i will give it for 20£ call me at 07725147228