OP listen carefully. Dump this piece of jink like a hot potato. That means fast.
This is what we are dealing with! Just look at the extent of the fraud by the MRSP.
The woofers in the mains, center, and surrounds are only 2.5" diameter! They state they go to 100 Hz and I bet that's a stretch.
They describe the mains as 5 way. A look at the driver configuration tells you that at the most they can 2.5 way. So the outfit does not know the correct nomenclature.
Similarly the surrounds are described as three way, at the most they can be 2 way. If they are anything else then it is a bigger mess than it looks.
Next the sub is passive. Modern receivers are just not designed to work with passive subs.
I suspect that the sub has a sort of misbegotten cobbled crossover to supply the woofer and other speakers.
If there was no decent instruction manual this should have been your first clue that this product is not legit.
Unfortunately you have fallen victim to fraud. You will have to see if you can unscramble the egg.