If the mistaken deposit was:
On Arbitrum but not USDC,
→ you can recover it using: https://peanut.me/recover-funds
(You must be logged in for the link to work)
On a different chain entirely
→ Contact support with tx details; recovery may not be possible depending on the chain.
Currently you can only recover your funds if you sent the funds in one of these chains: Base, Ethereum Mainnet, and Linea.