I withdrew around 0.7001363 BTC from one trading exchange to another around 14 hours ago and it still has 0 confirmations.  I reached out the sending exchange a few hours ago and they informed me that there is nothing they can do about it. 

What is going to happen to this transaction?  Is it stuck indefinitely?  Does it dissapear?  Is it returned to the sender at some point?  Should I have the sender follow up with any sort of action(s)?

I've never experienced anything like this, and anyone's help/information is greatly appreciated.

Thanks,

-ed