5G Promo Home Internet bandwidth really bad

I signed up for the 5G Home Internet $50/month, no limits, unlimited, etc. I was told that this was a first-come deal and I "got in." The program said to be restricting the number of users on the tower(s) so that it is not overloaded with traffic. Well, guess what. My 60-80 Mbps drops to 1-3 Mbps for the majority of the work day. So, pretty much useless...and not worth the $50. Has anyone had this problem and received any kind of explanation? They say they are monitoring the towers to make sure "bad actors/activity" is controlled (unattended bot use, humongous bandwidth hogging, etc.). This is not reliable for home-office use.