From their help article, it appears they can reverse mistakenly sent transactions.
If you sent money to the wrong account details and you don't know the recipient, you should first wait 7 days to see if the money bounces back automatically into your account. This will happen if the wrong account details don't exist with any bank or financial institution, meaning your money wasn’t received by anyone.
If your money hasn’t returned automatically within 7 days, contact our Customer Support team who can help to recover the money for you in the bank recall process.
It’s worth noting that the bank recall process can take up to 120 days and we can't guarantee a successful outcome.
In localbitcoins, I see monese is tagged as "medium risk" which by their definition means "The payment is reversible and LocalBitcoins receive the occasional report of fraud.", see:
https://localbitcoins.com/guides/how-to-sell-bitcoins-online#toc4.
Occasional fraud could mean the chargeback wasn't easy to achieve as I imagine users still have to go thru monese's protocols hence occasional or maybe there just aren't many people using them on their platform.
Can we know which exchange platform did you use and did you check if your buyer's account has a great reputation?
