Email

Did you see that message when you signed in with your Apple ID? If not, then it is a scam.

Did you provide any potentially damaging information to anyone? If yes, you'll need to follow up, for example, with a credit card company, Apple, your bank, etc.

If you gave you Apple ID password to the scammer, then

Change your Apple ID password https://support.apple.com/en-us/HT201355

Here is what to do after you change your Apple ID or password

https://support.apple.com/en-us/HT204071

And, here is some information on how to "Avoid phishing emails, fake 'virus'

alerts, phony support calls, and other scams:" https://support.apple.com/en-us/HT204759This

read also provides information on how to "report phishing attempts and

other suspicious messages to Apple."

Here is another read that covers scamming. It deals with the App and itunes Stores,

but it also has more general applicability https://support.apple.com/en-gb/HT201679