I have killed my bike 
It's recently had a service with new disc pads etc. Shortly after I got a puncture. So I took the wheel off to fix it (it an Alfine hub); realised there were too many holes in it to fix and couldn't get the thorns out the tyre so ordered a new one; while waiting for that to come I left the bike in the shed upside down.
When I fixed the tyre and tried to put it back on the bike there was no way I could get the disc between the pads, I ended unbolting them and then tighning them up again, now (obviously) the wheel is very hard to turn.
What have I done wrong and how do I fix it?
Thanks

It's recently had a service with new disc pads etc. Shortly after I got a puncture. So I took the wheel off to fix it (it an Alfine hub); realised there were too many holes in it to fix and couldn't get the thorns out the tyre so ordered a new one; while waiting for that to come I left the bike in the shed upside down.
When I fixed the tyre and tried to put it back on the bike there was no way I could get the disc between the pads, I ended unbolting them and then tighning them up again, now (obviously) the wheel is very hard to turn.
What have I done wrong and how do I fix it?
Thanks