I purchased my phone from Best Buy last October, but I want to try to exchange it for a new one since I'm having issues with my messaging. Do I have to bring the phone back to Best Buy or can I just go to Sprint? Also from anyone's experience... do they take a lot of time troubleshooting before they can issue you a new one? I want to go tonight, but can't get there till about 8:30pm, so if it's gonna take forever I'll have to wait until Saturday. Thanks!