I need suggestions about what to do about my work severely ripping people off?

(Sorry I can’t give any details on where I work or how they do it), there are some environmental issues with this too

I do believe I’m being paid to be quiet about this(my pay rate is extremely high for what I do)

I have spoken with my supervisor about this and I either get the shut up answer, or the you don’t understand answer, and my favorite the keep your mouth shut, it doesn’t matter answer….

Then the worst part is that I have to explain to the customers why their bill is so high…