turn your 3G off and your battery will last like 10x as long
I spot t-mobile, I don't even have to further as to what your 4G/3G problem is there. As for battery it could be old/defective if new etc. etc.
What phone? It's possible it doesn't support 4G. If so you could probably flash a rom that'll use HSPA or HSPA+ on T-Mobile
answer my question:
Huawei prism II
What about my speed? Is that good for 50 dollars/m?
$50 a month for those data speeds, unlimited calls & text, yeah