I have made a transfer from my bank account to metamask. Minutes later, I cancelled the transaction. The next morning I saw that my money if gone from my bank account and the money is not in my metamask. Can somebody tell me where is the money gone? how can i get it back? PLEASE
You don't do a transfer to your Metamask, you do a transfer to an Ethereum address (wallet address). Metamask is just a tool (wallet) to access an Ethereum address through a private key.
That being said, I don't know what you mean when you say that you sent money from your bank account to your metamask, I presume you are saying that you sent cryptocurrency to your Ethereum wallet from a bank account that offers that service.
Once started, transactions on blockchain can not be returned, although they can be canceled before it is conclude, to do that you need to send a transaction to your own address using the same nonce, but it need to be fast, before the transaction that you want to cancel be completed.
If you are serious, I suspect that you were victim of a scam, I suggest you study more about how transactions on Etheruem blockchain works. You also can consult all transactions to your address in a blockchain explorer, like Etherscan.