hi
Did you see this message when you click on the ETH to get your deposit address??
"The minimum amount for deposit is 1 ETH. Smaller deposits will be credited once they total this amount."
Don't worry guys, your ETH is actually there but not credited to your account until you have at least 1 ETH in total deposit and then it will show up which is crazy at these prices, most other coins are like 0.01 or above.
I had a similar issue when I was mining ETH, I used my POLO ETH address to receive payment and it would never show up until I reached 1 ETH.
There is another way to make it show up but you will need $$$ to purchase ETH to make it show up.
eg: You have deposited 0.2 ETH but its not showing up. You then use any other crypto or BTC you have in your account to actually exchange it, buy another 0.801 ETH and then BOOM you now have 1 ETH appear in your polo account..