Bad Phone and Internet reception iPhone 6 plus LA Sprint

Hi everybody, I'm new and it's my first apple device that I bought.

Place: Los Angeles, CA

Device: iPhone 6 plus

Case: Love Mei "aluminum case"

iOS: 8.3

Phone & Internet Company: Sprint

Issues: Poor phone & internet reception

WI-FI at HOME:

- Well, at home I have my modem and router to get WiFi, and my PC "windows" Tablets and Smartphone "android" also my old macbook get a great wi-fi signal around the house, from the router.

- But only my iPhone get a poor signal with one bar or point; I need to stay near to the router, and no more far than 7 o 9 feet to get a not bad wi-fi signal reception.

Phone and Internet Reception by Sprint:

- When I bought my iPhone came with the version of iOS 8.0 but as soon that apple released the updates, I updated my iPhone, now its at 8.3

- But when I'm trying to navigate on internet I get a really bad internet reception. But if you think that maybe is my data plan let me say that we (my family) have a data share plan, and only my iPhone has a bad reception.

At home we have a LG Galaxy S4, HTC One M9, Sharp AQUOS Crysta, and everybody of my family members has no problems with phone or internet service.

And look, some of them are cheap and I paid a lot of money for this phone.

At Los Angeles, CA when I'm walking with the family, wow sometimes my iPhone get lose completely the internet service, when the rest of the phones have full signal.

Example:

At the streets S. Western Ave and W 27th near to USC or Downtown LA its like BLACK HOLE lol yeah sounds weird but I have nothing of internet reception there. But I'm not living there, I'm live at Lynwood, CA near to LA.

Also when I'm at the freeway 110 (LA) trying to listen music. I have the same issues, when the rest of the family devices have full internet reception. (I mean full bars)

Sprint let you have LTE (*** is that idk) and 3G, same thing, with of without that still poor reception.

I don't wanna go to the Sprint's Store and ask for a refund and get an Android Phone cuz my friends will laugh of me, cuz they told me about those issues. sad 😝

Now, about the phone service until today I guess I didn't have no problem to call or receive calls.

And about the case, I tried with and without the case. And nothing, same thing.

I tried to reset the phone, reset the network settings, and nothing same thing, the issues keep persisting.

Please guys if you have an easy solution feel free to tell me. THANKS.