BB Storm :: 9500 Touch Screen Won't Open Anything?

A few weeks ago I bought my first Blackberry - Storm 9500, Grade A on ebay.Last week on holiday I left it in the glove box of the car for a couple of days and the touch screen stopped working. I could scroll and highlight but nothing would open.

Returning from my holiday I looked online and realised there was a reset button behind the battery cover.I pressed this last night and the phone worked perfectly again.

However this morning the phone was back to the same issue and now pressing that button does nothing.This is a full description of the issues;Green button works. Red button works, Return button works. Mebu button works. Handset lock button works.Camera button does not function.Volume up and down buttons do not function.Touch screen will scroll on menu and highlights apps, but upon clicking nothing opens.

So although I can press the gree button to answer a call - I can't make a call because I can't select a contact or numbers to dial.

I have bought a USB lead to see if the phone needs an update or to see if I can reset it but i've never connected a phone to my PC before so I'll have to look at it in the morning with the manual.I have personal data on the phone which I must remove if I end up sending it back - I expected to be able to use all the functions of the phone via my PC.