iPhone 4S Volume changing on its own
Basically over the past few weeks every now and again my iPhone 4S volume will randomly turn itself up and the ringer stays on the screen like the button is being held down.
It's happened randomly since I got the phone (on day of release from Vodafone) but has never been a problem till now. This weekend it does it nearly every time I touch the phone. I can't risk putting my headphones in because it would actually deafen me if it turned up on it's own and it annoys me that it does it in games and stuff as well.
I researched on the internet and have reached nothing conclusive. I heard one person say they went into their apple store and fixed it in seconds. I don't get up town often (especially around Christmas) and would like to avoid this obviously so I just want some advice.
Is this a hardware problem and do I need to get it replaced in store or could it be a problem in my config or apps or something? I'm not very Apple savvy so any help is appreciated...
Just to add I currently have a hard case on my phone. I took it off yesterday for a while to experiment if it was that putting any additional pressure around the keys but it did it without the case on too. Also the volume is only turning up, not down.
Thanks guys x
iPhone 4S, iOS 5.0.1