Did you clean the rim of the opening from the toilet tank to the bowl? Sometimes ours gets gunk on it and the flapper cannot seal properly. Also be sure the float or other mechanism is adjusted properly to fully cut off the water supply once the tank fills. If you can raise the float a little and the water cuts off, then you need to adjust the float - you can gently bend the arm on it.

I changed the flapper...didn't stop, so I changed the seat and it continues leaking as in did when I started. The water is disconnected with water in tank and it continues to drain into the bowl.

Too much water is entering the toilet closet and running down the center stand pipe.

Chain for the flush mechanism is probably too taught, so it doesn't seal. Make sure there is slack on the chain.

Time for a new toilet.