Mobile internet problem

Yeah i have a problem about mobile internet witch is on usb stick its 2gb version
and the name is Alcatel onetouch L850V

SPEEDSTICK LTE

afther some time using it it worked all normal usb flashing blue all perfect then some time later i get message from t mobile that i used whole internet traffic witch was 2gb then they tell that internet speed will be lowered at 64 kb << witch is so lame fail

then they later say that i need to activate something on their site you know pack parts with 200 mb and 500mb is there witch you need to pay what s that its big one non sense

so i wanna know do i need to clean every time before i reach 2gb internet traffic that this doesnt happen again this is again fail stupid mobile internet is meh still hope someone know how that all works i am not very good with internet on mobile

also i forgot to mention that signal is just one bar

Mobile internet problem