Is my 3rd time reporting a problem with my 2005 Mercury Mariner a charm? Could I be lucky enough to have the problems end now???

I had noticed that my volume knob hadn't been working properly for a few weeks, I would try to turn down the volume on my CD, or radio and nothing would happen, I would turn and turn the knob and the volume would stay the same...

Well one day I was going through the bank drive-thru and when I stopped to put my deposit in the thingy the lady inside said something to me, which I could not hear due to the loud music, I reached up and turned the volume knob to the left (to reduce the volume) my volume shot up to max loudness, no matter how many times I turned the knob to the left it turned the music up louder, now everyone in the 6 lanes of the drive-thru is staring at me, probably thinking what an ass for blasting my tunes.

I finally hit the off button, which was a temporary fix at the time. But now if I want to listen to music - I have to drive down the highway at 70mph with all the windows down just so the music volume doesn't rupture an eardrum, since I am poor I won't be able to get this fixed any time soon...