My problem with Poloniex

I started trading cryptos a few weeks ago and everything, for the most part, has been going well. The market is booming, I enjoy doing research on the different coins, and I am making a really nice return. The original exchange that I started trading on was Poloniex. Poloniex is one of the most common exchanges used my new traders. The few weeks I experienced the exchange was pretty good until the other day.

I decided to start trading with Bittrex instead because I wanted more options and liquidity. So I started to move my coins over to the other exchange. I sent one transaction on the litecoin blockchain and it went through no problem. Then a few days later I sent a larger sum of litecoins over to Bittrex. On Poloniex it said that the transaction was completed but there were no litecoins in my Bittrex wallet. I checked to make sure that I sent it to the correct address and made sure that I sent litecoin to a litecoin wallet. Everything checked out. Then I went to the litecoin blockchain explorer and checked if my transaction was sent. It wasn't! How could this be? I did everything correct and Poloniex fucked up. I sent in a ticket and it is still being processed. This greatly angered me and I will never use Poloniex again because of this situation.

Has anything similar happened to anyone else? If so please comment on what you did to resolve the problem. Thanks!