Is it possible to recover XMR that was sent through mymonero.com to freewallet.org? At first I tried to send my XMR(mymonero.com) to deposit XMR address of(freewallet.org) but it says "Something unexpected occurred when submitting your transaction: Failed to decode address (#63): Invalid address prefix", so I used the freewallet.org Monero Original deposit address and it went through. But then I didn't received it on my freewallet.org, I contacted their support they said it was mistake that I sent XMR to XMO and my XMR coins are stuck now. My question is that can this be recover using any tools or something like that? because if this is not valid at the first place why mymonero.org have transaction id on sending the xmr to xmo address? I'm sorry I'm newbie at this, hopefully masters like you can help me. Thanks in advance.
It is impossible for XMR to become XMO during a blockchain transaction. What actually happened is that XMR was sent to an "XMO address" which was interpreted as an XMR address. Therefore you sent XMR to an XMR address, and it's still XMR. You sent the funds to an XMR address they were not expecting you to send funds to.
Since they know the private keys to their XMO wallet, they should be able to use those private keys on the XMR blockchain to set up a wallet to get access to the the XMR funds that you sent. There is nothing you can do to reverse the transaction, because cryptocurrency transactions are irreversible.
If they are not willing to bother to do this for you, then please document the situation and notify the Monero community. There have been other reports of problems with freewallet.org documented here: https://www.reddit.com/r/Monero/wiki/avoid