Nah, don't return it, Type 2 has always been a premix. For the price you got it, and now that you've flushed the system, and filled with Type 2, as I said, check the concentration with a AF tester. If not up to the concentration, do radiator drain and fills until you reach it. Yes, some waste but you've come this far already.
fwiw, I had to do similar when stealer used original green with a head gasket job.
And, from now on, just do a radiator drain fills more frequently with the Type2.
If you got Type2 for $10/gal, even though it's a premix, I sure wouldn't trade it for a universal coolant with 2eha.