...receiving their data from(?)
You are asking essentially for 'free high speed mobile internet'.
It's 2016- Gotta pay to play, amigo(!) Find a cellular provider that suits your needs better while stuck at work.
My home internet doesnt have wifi hot spots near my job. I currently use my samsung s6 edge to create a hotspot to use my laptop while at work. This sucks because IT DRAINS my battery and my data...
are there are hotspot devices that i can use that dont go into my data plan?