Just a quick update. Went back to apple yesterday to get the screen replaced as it became unusable and the genius did a diagnostics test which said I was getting lots of temperature warnings. Therefore they decided to swap it for a new phone for free (even though it's out of warranty)
Also to those people who were saying it was my fault, Apple made the right decision etc etc. Well it turns out the reason they were willing to swap the screen for free was because the crack inside was classed as a defect under consumer law. The genius also said that each customer is entitled to make one claim under this law per iPhone which allows them to get the free repair.
Obviously the reason I was hesitant about this was because they said my phone was bent as well which wasn't covered and that I would have to pay for a new one if it didn't go on but it turned out it didn't matter in the end anyway.