Did you set up your wallet yourself? Blockchain wallet’s are often used by scammers, because it’s easy to set up watch-only wallets where you are actually seeing funds controlled by someone else. If you did not set up your wallet yourself, you should check whether this is the case.
Otherwise, check on a block explorer whether the transaction went to the address you expected and has actually been confirmed. If it’s just not showing up on your blockchain wallet, you may want to find some support articles on “How to rescan”.
