Q: keychain verification code is not match

i tried to used iCloud keychain for many times, but when i typed in the verification code which i received by my phone, i was told that the code is not match...strange. i had tried for many times, and now it told me that:"because your security code was incorrectly entered too many times, you must identity with apple support before trying again." and i don't know what happened and what is the next.