I sent tokens to the address which i think does not exist and I mis spelled it
I might suspect that this isn't the reason. You might copy-paste the wrong address. Chainlink address is an ERC20 wallet and you store it on MEW address or in hardware wallet which is Ledger Nano S. If the address were lack or miss-spelled at least 1 letter or number it shows error and it might not proceed any transaction.
If you're concerned is to recover your lost chainlink, my answer is no. Once it is completed, then, it is a reversible transaction. If you have no access to the wallet where you've sent your link token, the chances of retrieving it are having positive.
This is what im thinking too that he might have some clipboard malware for him to paste up a different address but he mentioned that he input up a wrong letter or number? Its impossible for you to
type one by one when it comes to keys or even on address which its unlikely to happen when you simply just copied it.
@OP, sorry to hear on such situation but theres no one can help you on retrieving those coins because we know that crypto transactions are irreversible which means once you have sent it
on others address then theres no way on getting it back unless if the owner of said address will be considering on giving it back but its impossible.
Make sure that next time you should copy the correct address to avoid the same mistake.