Just Brakes Price Gouging Denver, Colorado

After hearing a grinding sound from my back brakes, I took my vehicle in to Just Brakes to get them repaired. I too, saw the sign at the front counter for all four brakes done for $99!

approximately one hour later The Just Brakes Mechanic called me and told me it would cost me $534.00 to fix my back and front brakes. I told him that there was no way that I could afford that. I was told my rear rotors were beyond repair and my from rotors needed to be grinded and would then be ok. 

I told the mechanic to put it back together that I would pick up my vehicle. When I got to the shop my car was still disassembled. The mechanic told me the rotors were severely damaged. again I told him I couldnt afford the $534 price. 

He said he would not charge for the bleed and would only fix the rear brakes for $400. I was told that I would have to return to get the front brakes fixed soon, as they would start to grind in a few days.  

About a week later I returned to the same shop. My front brakes were grinding and I fiugured what better place to take them than the place that already knows what the issue is.

This time my quote was for $600! I know I should have just taken my vehicle somewhere else. I only have one vehicle. So I felt I had no choice.

Now I can't tell you how angry I am. What can I do? I plan to notify the better business bureau. Do I have any legal standing to sue? Any feedback would help.