Can't get the speed I'm paying for, how can I get my money back?

Dude I'm tired of being played by Comcast. 

You are fake business and that's it!!!!
I'm paying for Gigabit and the guy came here with his gear and said it was fine.

It's not fine.
I used to have at least 400mbps now I can barelly have it stable at 50mpbs.

And you're still charging the same.

How you sell me something like that?

What the problem with you!!!

I called em another day to move the cables to the other side. 

I got a text message saying that the technician was here and nobody was outside and they litterally never showed up!!! And I paid!!!!

My question is: Why? Is this is just like that? We need to swallow this type of continuous situations happening without no chance to get any better?

So your business is litterally selling people the "possibility of getting" a certain possible speed if you wanted to?

Is this?