Ah, this is not a Poloniex problem - the coins never arrived there.
You send your BTC with a very low fee. Search this forum for " unconfirmed transaction " and you will find many similar problems.

When you don't do anything, there are a few options:
- this transactions fails, money is returned
- depending on your wallet it is possible that this transaction is transferred again and again, in that case you have to stop the transaction. Because it's not visible in blockchain anymore (follow the link you posted earlier), I guess this isn't the case
- some miners picks it up and confirms the payment finally

Maybe you could refresh your wallet and see if the money already returned. If not: search the forum for "uncorfimed transaction"; there is a lot of information in those threads.

But: Poloniex isn't at fault here, they simply never received anything.