Finally heard back from Changelly and it looks like they are just keeping the money. As some have mentioned very scammy. But it is spelled out in their terms of use so I guess lesson learned read all that thoroughly before using a service and understand, too, how your wallet will be sending the coins.
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Thank you for your query.
As we can see, you've sent the funds as a contract transfer instead of an ordinary transfer. Please note that we do not process such transactions, and there is no way for us to credit or refund your coins so far.
We also cover this in our Terms of Use clause 2.9:
https://changelly.com/terms-of-use.
We appreciate your understanding on the matter!
Sincerely,
Changelly support team
There is no technical reason why they couldn’t process your transaction. If they are capable of recovering ETH sent to a BSC deposit address then surely they can recover ETH from a Base address. Their terms are very arbitrary and demonstrate why they are so untrustworthy.