franklin t10 from sprint to tmobile

I’ve had the Ft10 for several months watching many movies and computer internet never using up the .49 gb (500mb plan per month) 

Now that we have been forced off the reliable sprint network onto tmobile the Ft10 has suddenly started using enormous amounts of data

tm upgrades the plan and yet it’s using data line NEVER before in the 8 months plus use

Recently they upgraded me to the 10 gb plan but without EVER answering why the sudden data increase

Sprint sold me the device saying it would never use up the 500mb and it never has until the promised “no changes” in the switch to T-Mobile 

it’s always had a tmobile sim

I suspect there switch altered/CHANGED the data usage

GIVE ME BACK WHAT EE HAD!!!

and why can’t I check the data usage on the Ft10 via the web or the app??!!??

I can check the usage on my two iPhones but not the hotspot??!!??