Poor Internet speed and not reliabity

I too get horrible speeds and as low as 18mbps! How's that for the most reliable 5g service? I don't even get 5g readings and this constant buffering is getting worse by the day and I have numerous towers around me. I get better speeds when I have only 2 bars on the gateway than when I get 5 which was once and just briefly. I have had the gateway for a year now, have bought an expensive booster which did help some but should not have to spend that kind of money to get the service promised. I had AT & T previously and never had these issues and I wish I had never left them because I can no longer get that service at my location now. T-Mobile in my opinion has lost its customers a lot of good service with the promise of faster speeds and better service. Liars!!! I work from home occasionally and can not get on the sites needed now with t-mobile due to the constant buffering. And I am tired of having to constantly call them for solutions. My time is worth money and they should reimburse me for all my time spent, messages and phone calls that I never receive or receive hours later. End of rant. Thanks for listening.