is it one bought from argos? There should be instructions in there but pretty useless, go back to where you bought it and ask them. if it is second hand then i am not sure.
Check all poles to make sure they are elasticated,check seams etc.
We had no end of problems with pro action tents, we had 2 6 man tents in 6 months both were faulty in some way.
Switched to a rage with our latest acquisition, they are alot better.
hope i have helped!