I had the EVO, upgraded to the EVO 3D and just upgraded to the EVO 4G/LTE last week. Even though it was never explained to me until after I called Sprint Customer Service for the 4th time due to poor network signal and no 4G signal where I used to get 4G service, I found the folowing information interesting.
The current 4G network (which is WiMAX) that the regular 4G phones (EVO, EVO SHIFT, EVO 3D, Galaxy, etc) work off of is being phased out. The new 4G/LTE network is not available everywhere yet, but is in the process of being available; however, as of the date of this post, only old 4G phones can get 4G service, and if you're like me, and upgraded to the 4G/LTE, we are restricted to only 3G network servce until 4G/LTE is up and running, at which time, the old 4G phones will no longer be capable to work on the 4G network.
That would have been good to know when I purchased the phone.
All of that information is available for the asking or a simple internet search. Sorry that the sales rep did not explain that to you. A lot of the reviews I looked at before deciding on this phone stated that is was not a wimax phone. You have a choice to return it if you are still within your 14 day period. If not then you will have to wait for LTE. I seldom used the 4g wimax so I was not worried about only having 3G service. Since 4G LTE is about a year away for me I am not going to sweat it.
I guess my greatest misinformation was that I thought the EVO 4G LTE would also work on WiMax in addition to LTE, and not in lieu of. It also doesn't help that so many 3G towers are down in my area (supposedly due to upgrades and severe storms), that I purchased a phone to get the best 4G available and instead, I'm getting the worse sporadic 3g available.
Maybe I'm weird but I did a ridiculous amount of research before upgrading. Even doing a little research (ie read any professional review from someone that has actually used the phone on Sprint's network) on either the EVO LTE or the Samsung Galaxy SIII on Sprint would have told you that they don't have 4G LTE up and running and these devices are not compatible with WiMax.
Sorry to hear about your issues but you are in the window to cancel your upgrade and return your phone (14 days).