Hi guys, I was just wondering if anyone had any experience with trading in their phones for a new or refurbished one, because I have an iPhone 4 and some problems are starting to come up. One is the home button becoming unresponsive, another is that there is one tiny grey pixel on my display, not sure what it is. Couple more but you get the picture. So my question is, if I am on 4.1 jailbroken and unlocked on tmobile, when should I go trade in my phone? Will they even replace my phone? I bought this phone from someone on this forum and he didn't have the original box for it but he said that I still have warranty for it. What do I say to them when I go?

Thanks in advance!