So, if we use your point, then I am supposing you can tell me where in the Bible it says, “God hates polygyny.”
You are very right, he does hate divorce, but that is never said about polygyny. In fact, you are expecting me to take your word over God’s when you say that “it was NOT the way GOD had designed it; but how man had distorted it.” In the absence of scripture reference, your point is not one I will debate.
Regarding God endorsing it, I have already given you one example. See http://biblicalpolygyny.com/wiki/index.php?title=Endorsed_by_God for more.
2 Samuel 12:8 I also gave you your master's house and your master's wives into your care, and I gave you the house of Israel and Judah; and if that had been too little, I would have added to you many more things like these!
If possible, this verse is a little stronger case. Samuel is relaying a message from God to David where He tells David that He gave Saul's wives to him. As if that were not enough, the Father goes on to tell David that he would have added more things like these if this which had already been given was too little. In fact, if we research just a little more we see David being referred to as a "man after [God's] own heart" in 1 Samuel 13:14 and Acts 13:22. Similar to the situation with Joash above, it is hard to reconcile polygyny as sinful when God credits himself as giving David his wives.
NOT 'similar'.
Were not widows supposed to be taken care of in the OT?
Did not Onan 'sin' by failing to give his dead brothers wife an heir?
Did not GOD fail to take more of Adams ribs for wives for him?