why TMobile home internet so bad

I got the Home Internet at the beginning of the year and it was working just fine up until about a month ago. I've had it less than 6 months and regret the decision now. I feel like I have been scammed.

I could understand it being slow for a day, even a week, but over a month and steadily getting worse?

Just today, It took an hour to download just 2GB of a game. I started the download at 1AM and only had that device connected to the internet. At 2AM I looked and only 2GB had been loaded. I wanted to throw the internet device into the street.

Why was it running fine for just a few months and then service just drops dramatically for everyone who gets it? It seems like they are just milking us for a bit of money and then toning down the internet for users that have had the service longer than 4 months. It's a disgrace. 

Edit: 3:30 in the morning, 2.5 hours since I started my download and I am at 2.5GBs downloaded. Absolute garbage service.