mouse keeps scrolling up when i scroll down

I used a very small flathead screwdriver to pry open the top panel (I'll call this the 'hood') of the mouse. But then I told myself I want the mouse to work at its fullest capacity, and so, I did the following (I understood fully that it may not work and was well prepared to purchase a new keyboard set).I turned off the mouse and removed the batteries. The left and right buttons work and clicking on the wheel has allowed me to scroll that way. Tried all kinds of suggested solutions but to no avail. I've been having the exact same issue for several months now. It worked for me!! If you do decide to follow these instructions please know you're doing so at your own wrote: I took my time and treated things delicately. I don't feel too comfortable suggesting that a person do this because, as I stated earlier, I understood that it might not work. I placed the panel back onto the mouse, replaced the batteries, turned on the mouse, and wala, the mouse's scroll wheel sends pages forward and backward without any problems whatsoever. I placed alcohol onto a q-tip and while I turned the scroll wheel I allowed the q-tip to rub against the small black wheel (this cleaned it).

Under the mouse's hood I saw a small black wheel (this small wheel moves when I move the scroll wheel back and forth).

Mouse keeps scrolling up when i scroll down