The lock button on my iPhone is completely jammed so i need to exchange my phone. Will I need to take my phone to the 3 store because I bought it from there, or will I be able to take it the apple store? Also, will I need my warranty papers, and other papers, from 3 if i'm taking to the apple store? And also would I get a new phone there and then, at the apple store, or would they attempt to fix it? And would this cost?