Personally, I used the advanced exchange online and received a brand new phone. With that said, I would just take it into the sprint store and tell them the KB flaked out and they should give you a new one on the spot as long as you have had it under a yr.
Let me tell you about my experience with the advanced exchange:
So I go online and order a new phone. Get it 2 days later. The very next day I send the broken phone back in the self addressed envelope they sent with the new phone.
I track the package via the website they provided me with to make sure they received my phone and they did in like 4 business days. A short while later I check the website again and according to them, I sent back the wrong phone. They claim I sent back a diamond. Um...?
So I call customer service as soon as I noticed them and explained the situation. The first person I talked to didn't even know about the advanced exchange program. Explained my situation and they couldn't help me. It got escalated and I talked with a supervisor. They couldn't figure out why they were saying the phone I sent back was supposedly a diamond. The lady I was talking to saw that I've never had a Diamond activated on my account. So she gives me the number to the warehouse where I sent the phone, no dice. They gave me the run around and told me to call customer service.
I called back in to customer service and got the issue escalated to a manger. She was going to "investigate" the issue herself to get this resolved. She was going to call the warehouse herself and see what the mix up was. She took down my name and number and said she would call me back. She never did, no surprise there right?!
So the next billing cycle I get a $55 charge, which I fully understood and expected because that's what the website said. On the website provided it said that I could be charged up to $200 since I "sent back the wrong phone." So I never got a call back and called sprint back up but I couldn't get in contact with the manager who I was talking to before. So I had to start all over again. I had to rexplain the situation even though my account had tons of "notes." It didn't help...
So the same thing happens again. They give me the run around and toss me around like a hot potato. It gets escalated to a supervisor and I'm suppose to get a callback, never did. this went on for about 2 months, at this point I've spent at least 5 hours on the phone with sprint.
I check my next months bill online and there is a $200 charge on my account. WTF?! So I get on the phone AGAIN. Start the process over, AGAIN. Explain my story, AGAIN. Got the same run AROUND AGAIN. Each time I would call customer service, they would put me on hold for at least 5 minutes so they coudl read the "notes" but I still had to explain what was going on.
Why take notes and/or read them!?
Since I was getting the same run around, I went to the Sprint store to plead my case and show all my evidence that I had sent back the right phone with the tracking etc etc etc. Said they couldn't help me at the store since used the online advanced exchange and told me to call retentions.
It took all of 5 minutes TOTAL and the guy I talked to put in a request to have my $200 charge removed. I just looked today, after 2 1/2 months and the charge is gone. I wasn't about to front $200 on their screw up. They were suppose to give me a $200 credit but I wasn't going to pay my phone bill + the $200 charge this month.
So after all the headache, I'd just go to the sprint store. If you do use the advanced exchange, I wish you luck.