Steam Wallet
Steam Wallet is prepaid balance attached to a Steam account. It is not a general bank-withdrawal balance. Steam's limited refund policy may cover Wallet funds bought on Steam within 14 days only when none of those funds have been used.
Why the lock matters
Valve does not offer general Steam Wallet cash-out. Value added to Steam Wallet is normally spent inside Steam rather than withdrawn as cash.
The limited refund exception
Steam says you may request a refund for Steam Wallet funds within 14 days of purchase only if they were purchased on Steam and none of those funds have been used. That narrow refund route is not a way to withdraw an older, partially used, gifted, or market-earned balance. Steam decides refund eligibility under its current policy.
SteamVaults settlement path
SteamVaults currently accepts only Sack of Gems. After you approve the Steam trade offer and the bot confirms receipt of the supported Sack of Gems, USDT is credited to your SteamVaults site balance. Withdrawing that USDT on Polygon is a separate on-chain step; the value does not enter Steam Wallet.