First off, this is Sprint. Never, ever trust a word out of the mouth of a Sprint employee. They are poorly trained, they are on the lowest rung as far as information, the system they use to check towers is NOT real-time, they often do not work directly for Sprint (call agency), there is generally a culture of quantity (get the customer off the phone as fast as possible) and lastly the turnover rate is about 6 months. So, even if you get an employee who wants to improve their standing and has been around awhile, most likely that person will be quitting very soon.
Next, understand that Network Vision is ongoing in all markets.There are over 38,000 towers and Sprint is replacing the equipment on EVERY tower. You have to factor in permitting, local laws, contractors and right now the biggest problem backhaul. By backhaul I mean that the companies that are responsible for laying down fiber optic cable (such as Comcast, Centuyrlink, Cox, AT&T) are being very slow to do so. So, while upgrades may have been made, there often is nothing to hook the new equipment up to.
Lastly, you might check out
s4gru.com. This is an independent site that has the most current information (passed to them from internal Sprint employees and contractors) about the rollout. In their forums there is a market area where you can check on the progress of your area. If you become a sponsor (I'm not, I'm not even a member) you will have direct access to exactly which towers are being updated where and when.
Again, none of this is information that front line CSRs (gatekeepers) have access to.
I know that doesn't help you with your current predicament, but you may find some info on s4gru.com that will be helpful.
P.S., you can't cancel over this. They have provisions in the contract you sign that state that they do not guarantee coverage. This has been fought successfully in court by a few people. Just depends on how badly you want to fight it and how deep your pockets are. You can also try
dan@sprint.com which is Retentions, filing an FCC complaint (which will have Retentions calling you) or placing your phone on roaming and roaming with excessive data for a few months. Sprint will terminate you ETF free if you do that.