Your camera works fine. It's your metering that needs improvement. Overexposure in this case probably means you're pointing the camera at something dark. But "overexposure" even by two stops is a subjective term so it would help to see some of the pictures you think are problematic, without edits. If you could post or link to one or two, please do. I could then help you a bit with metering and exposure.
There's not much use for auto ISO. Ideally you would shoot at the lowest ISO possible (meaning not just the lowest setting, but the lowest that enables you to get the shutter speed or aperture you want) and then change either the shutter speed or aperture. For action, you're probably thinking about freezing motion, so you want to fix the shutter speed at say 1/500 in S or T exposure mode and let the aperture fall where it may. This is subjective but personally I'm not an ISO fiddler, and most pros aren't. I set to the lowest possible ISO and stay there. The metering mode itself is matrix, center or spot, and neither of those matter as much as how you use them, and they're completely irrelevant if you use a light meter, which I recommend.
Shooting RAW, by the way, is not a fix for this. A bad exposure will be just as bad in RAW is it is JPEG, and white balance has nothing to do with exposures being blown out. I recommend RAW, but avoid shooting with the goal of repair. Suffice it to say correct exposure is the best starting point. This will take time to learn. You may also email me from my website.