My wallet password was not compromised but my bitcoins have gone missing from my wallet
It is very difficult to know this with absolute certainty. And even if it is true, there are other ways to have your wallet compromised. Blockchain.com offers some rather insecure backup options: by email, cloud storage, etc. If a backup is compromised, it doesn't matter how strong your password is, the attacker won't need it.
Do you know what replace by fee means?
Replace-by-fee (RBF) is an optional flag that can be added to a transaction, to signal that until confirmed, it can be replaced by a new transaction that spends the same inputs, with a larger fee. See this question for more info.
Can I find out where my bitcoins went with the wallet number?
You can view the transaction that used your bitcoins as input, to see what addresses they were paid to. This is all public information stored in the blockchain, but addresses are pseudonymous by design, there will be no info about who took your bitcoin, or where they reside.
A wallet is software that controls a collection of addresses, but as with addresses, there is no public info available that will tell you with certainty which addresses belong to which wallets, or which wallets belong to which users.
Can I speak to a person atBlockchain to discuss my problem?
If they have a customer service department, then perhaps you can. But keep in mind they are just a business that works with Bitcoin, so they have no special position of control or power over what happens on the blockchain.
How can I recover my bitcoins?
You likely cannot. I would suggest contacting blockchain's customer service, but there is likely not much they can do. If you lost a substantial amount of money, you could contact your local law enforcement to report the crime, but again, there is likely little they can do to recover the funds.
How you secure your funds is a big question for Bitcoin users. Some methods are more secure, while others are less secure but easier to use. I would advise not using blockchain.com's wallet if you are looking for a secure storage method.