Every order (as well as alteration and cancellation) is written to the blockchain. If the parameters are not met your trade will fail and the funds will be reverted to your wallet. Keep in mind that the miner fee that was initially paid is not returned in the case of a failed trade. The higher the miner fee your transaction is sent with and the greater the slippage %, the less likely your trade is to fail. Since DEX's are decentralized this means no more contacting customer support and having to wait for a refund- as refunds should automatically process!
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