Most if not all exchanges require you to attach a message when you send them XEM. If you forget to include the message, you will need to contact the exchange. Due to the nature of the blockchain, there is no way we can reverse these transactions.
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Was that a question, or an answer ?
iâm sure this message was pinned as a hint not to forget the message when platforms require it. 
Exactly
What if we forgot to include the message and we contact the exchange but they say they cannot accept it without the message? Surely we need to resend the transaction from the wallet with the message that they need before they can receive the amount? If this is a required field then it should be set as such in the wallet by default even if its only for exchanges.
Your XEM will always be âacceptedâ if you send it to a real address. Exchanges make you include a message, as that is THEIR method of distinguishing accounts, as they have everyone send XEM to the same address.
please help me 
I just forgot to include the message on sending nem on changelly what should I do? Changelly still donât answer to my email, will I get my money back? itâs worth 0.55 BTC please help me,
Yes changelly will help you get your XEM back. There is nothing I can do, they are the ones with your XEM. Make sure to open a support ticket with changelly.
thank you very much
I am in the same exact boat as you. Please update me with your status and Iâll also update you with my status. I sent 9000 XEM to Changelly and forgot the darn message. I opened up a support ticket and attached a picture of the transaction on NEM explorer and i also sent them a picture of my nano wallet account page to prove i have access to that account deeming it is my account.
I messaged changelly on their facebook page and they said they will refund my nem, but our conversation cut on the confirmation of my refund address. I guess they are close on weekends. Have you receive your nems?
Changelly still donât give the refunds, there are growing number of failed transaction on changelly keeps on refusing to process those refunds.Is there anything we can do here for them to process our refund? itâs not just only nem but xrp, eth at btc.
I have heard people having good luck with contacting changelly about a ticket on twitter.
do I have to tweet them or direct message only?
My understanding is that you and changelly need to âfollowâ each other to send private messages. I assume tweeting @ them is your only option.
I cannot find a message in my Lightwallet, where is it?
The exchange site will tell you what your message should be.
I sent 5000 xem but the message was not copied. where is my money?
your XEM is with the exchange that you sent the XEM to. You need to contact the exchange to get your XEM back.