NOT getting the 300 megabytes I pay for every month

I get between 20 and 100 megabytes seldom if ever do I get the 300 I've been paying for every month This started about 2 months ago prior to that I was getting much closer to the 300 so I feel like I'm throwing my money away cuz I'm not getting what I pay for not even close ☹️👎 I spent a good hour last night on the phone with tech support They ran a bunch of tests told me somebody would call me back for an hour that was a day ago ☹️👎