<human>: Can you condense the text into a few key points?

I'm located in West Michigan, and have been having loads of issues with both calls and texts on both my wife's and my Evos. About 50% (not kidding) of calls during peak times (about 4-6:30pm) go straight to voicemail, which they admit is a network capacity issue. I've been a fairly happy Sprint customer for about 5 years, and never had issues until about 2 months ago. 

I've called about half a dozen times over the past couple of weeks, and very cordially jump through all of the same hoops to "troubleshoot" the issue with each different tech I speak with. They each say "well, lets give it a few days, and I'll check back with you and see if it has been fixed". It thus far has made no difference at all, and I still have the same service issues. I've been calling and being friendly in an effort to build up my case for cancellation without penalty.
<bot>: I've been missing 50% of my incoming calls for the past two months on Sprint. Is this grounds enough for termination without penalty? What do you think my chances are?