Gas fees (also known as transaction fees) refers to the cost of carrying out a transaction or executing a contract on Ethereum (and many other networks). This fee is consumed by the parties running the network in order to process a transaction (that can either succeed or fail). It is the cost of computation, and is not charged or collected by MetaMask.
Due to the nature of the blockchain, transaction fees cannot be refunded!
For more details on high gas fees, check out this article: Why are my gas fees so high?