Jail broken AT&T iphone 4 for T-Mobile. Why can't people hear me?

I bought the jail broken iphone 4 back in May and before it used to make phone calls just fine. After a couple months people can't hear me, but I can hear them. I can make phone calls and people can call me, but I don't know what the problem is. There's no water damage or anything. What should I do?

Btw, I have good service all the time, so it doesn't make any sense.

How to transfer photos from my Iphone?

I have a bunch of photos on my Iphone that I would like to save because I have to reset my whole Iphone. Is there any app that I can use to keep my photos in and then download the app after I reset my phone and my photos will be there? Possibly videos too?

How much MB/GB would I need?

So I want an iPhone 4S NOT THE 5! Anyways I want to know how much MB/GB I would need, I only use kik, Instagram, twitter, google and YouTube! I know youtube videos use alot of MB so I would only use it at home, same with google (like my home Wi-Fi) I would only use the other apps at school & when I'm not at home. I send around 30-50 kik messages a day & post about 3 pics on Instagram a week. Twitter I send about 3 tweets a day!