A Worm in my Apple! Anyone Else Having Ongoing iPhone Network Problems?

Near the end of 2014, I purchased my first iPhone from the Apple Store in Green Hills (Nashville). The man who sold me the phone recommended T-Mobile as having the best-priced service for what I needed, and I left the Apple Store with a T-Mobile-compatible iPhone 6 Plus for a hefty chunk of change.

By the next day I was having issues receiving calls when at home, dropped calls when on the road, and connecting to the internet. For a month or so I felt like a volleyball as T-Mobile would assure me I had a defective phone, and Apple would assure me the problems were with T-Mobile. After going through various trouble shooting and resets, the problem would seem to be fixed for a few days, but soon I would lose the signal at home, or experience increasing dropped calls or not be able to connect to the internet.

After making numerous calls to Apple I got a case agent who would trouble shoot for me, and he finally convinced me the problems were with T-Mobile. I took my phone back to Apple, got a new Sprint-compatible phone, and I went to the nearest Sprint dealership to set up service with them in Dec. 2014. I wish I had saved that rep's name, because he told me if the problems persisted after switching to Sprint, he would upgrade me to a phone with more memory.

The Sprint service was much better than T-Mobile and I have never had trouble receiving or sending calls at home, but frequently when I am away from home, I get network errors. In the suburbs in a 10-mile radius of Nashville, in businesses, on the major roadways, and when off the beaten track, I often cannot send photos or get on the internet or do my virtual business. For nine months I have called Sprint periodically to reset things, and I get my network back for a few weeks.

However, Sprint has been telling me the same things T-Mobile told me: there are no outages or problems on their end and the only reason I have to reset my phone so often is it is a defective iPhone.

When Sprint called Apple last night to connect me, I was told there were no case notes of my previous issues. The supervisor said there was no record of my making numerous calls and no record of my old case manager. Jonathan B, iOS Senior Advisor informed me I could take a screen shot of any network error message and take them to the Apple Store to see if they would replace my phone, but his entire attitude was suspicious and almost hostiles as he reiterated there were no case notes and repeated himself multiple times that it was impossible someone would get two defective iPhones, and that they were getting no complaints like mine from any other customers.

So here's my question:

Are Any Of You Experiencing Similar Connection & Network Problems With Your iPhones?

Am I REALLY the only person out there who has had issues with two iPhones in a row? Let me hear from you, because my Apple Care may be up pretty soon and I need to get this resolved before I have no options. Since I contacted Apple AFTER I had called Sprint and had them reset everything, my phone is working fine now and may not have the same issue for several weeks.