The current fastest and cheapest transaction fee is 420 satoshis/byte according to bitcoinfees.21.co (while you only paid 155 satoshis/byte) so Its probably a fee issue, your transaction will take sometime but eventually get confirmed and you will see it in your account as completed so no, there is nothing to be worried about.
As for the second problem, Poloniex should give you the TXID so you should show it to the Livecoin support. Livecoin is somehow a new exchange so I'm going to assume that the problem is either coming from them or you sent the funds to the wrong address.
That's good to hear, although I did not know about this part. What can I do in the future to prevent this from happening?
I have a ticket with Poloniex and it is "being processed" so hopefully they can assist. I check my Livecoin wallet address to where I sent funds from Poloniex and they match.
Thank you!
You can't do much for the fees issue because you are sending from one exchange to another and not from a wallet that you own. Wallets usually give you the ability to change the fees or set a priority (normal, high etc.) In order to get your transaction confirmed in a small period of time, exchanges however, don't let you do that.
