Cancel Mobile Hot Spot Service Only

I recently moved to a much more congested area in another state near a big city. I need to cancel my Mobile Hot spot because it seldom works without significant buffering or drop-outs. I also have T-Mobile cell phone service which works OK. How do I do this? I currently have a device balance of $119 which I'm willing to pay to simply cancel the subscription plan.Thanks for any help anyone can give...frustrated!