I have this same problem. If you don't use flash, your shutter speed is too low and it makes everyone and everything blurry. If you do use the flash, they look pure white and like a deer in the headlights. It seems like there's no middle ground.
My cameras flash is beyond harsh. It has customizable flash strength, but even at the lowest setting I could go at, people still looked like they were in a police station getting their mug shot. I took a piece of toilet paper, folded it in two (my flash is REALLY bright), and scotch taped it over the flash. My photos come out a lot less harsh, now, and I literally didn't spend a penny to fix the issue I had with it. I will note I didn't put the scotch tape over the flash itself. I don't know if that would affect it any, but I didn't want to find out. I taped right above and right below the actual flash, and the result is much more natural-looking faces. Plus the people I'm photographing don't complain as much, cause the flash lost a lot of its harshness
Anyway, I hope whatever problem you have gets resolved.