Data usage higher than it should be.

Sounds like phones have apps that are using inordinate amounts of background data. I suggest going through the app permissions and disputing that where possible. Social media and email apps that refresh often can eat up quite a bit of data. 

https://www.t-mobile.com/support/account/check-your-usage would be a good reference.

As far as the Franklin T9 goes, are you looking at this: https://www.t-mobile.com/support/devices/mobile-internet/franklin-9-mobile-hotspot/data-usage-franklin-t9-mobile-hotspot or the "cycle" message that appears on the hotspot display?

pepsiman wrote:

Yes.  TMo doing some funky "calculations" here.  I don't use my phone much except for email/web surfing.  Don't stream, and for 99% of the time, I am on WiFi.  These past couple months, TMo has been completely falsifying my data usage.  My phone is only reporting 419MB of mobile data usage.  Yet, somehow, according to TMo, I used 4.7GB.  I can understand small differences in data usage.  But TEN times the amount reported?  Yeah, ok.  what kind of crap is this.  In all the years I have been with TMo, never had a problem until these past few months. 

T-Mobile claims I used over 100 GB in less than 3 weeks on my T9.  There's no way.  All I do is watch Netflix now and then, browse and check emails.  When I switch over to using my prepaid phone data from a different phone company,  I do the same activities and never run out with only 2 GB of data on my plan. It isn't a rogue app or any of that nonsense they claim.  Maybe a class action lawsuit will fix the problem.  Nobody likes getting ripped off by big companies who know you need the service they offer.  It IS crap and pretty stinky at that.  

I’ve been with Tmobile for 1 day and its showing that I used 22gb of data, there is now way possible, I check emails, order on amazon, watched a video for less than a minute just to check for lagging this afternoon, something is going on, I may have to switch back to my other carrier, this aint right

If you are domestically roaming then you will see weird usage because the towers not controlled by T-Mobile doesn't real time send data usage to T-Mobile.  It can take up to 2 months at times for it to show up.  Most plans with limited data plans often have a cap per month of domestic roaming in where the roaming provider governs.  What is reported by partners will not always show up till much later or at times may be higher than what you think it should be.

One thing i noticed about data meters on phones are often HIGHLY inaccurate.  For example look at your Google Play Services it CAN use 2GB of data a month and often it only shows a few hundred MB of data in the foreground.

This goes with ALL carriers in the US and some other countries.  If you ever us a desktop computer while using tethering you computer drastically uses more data than you think you are using.  My desktop currently used 2.1GB of data in less than 24 hours.  For most of the day it was just one with the monitor just turned off.  For this month as well as windows patch day I've literally hit over 90GB.