Someone with apple id sa4@icloud.com is purchasing from app store by my credit card and it still charged for purchases I didn’t maje

You probably are being scammed.

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 a scammer, then

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

Here is What to do [before] or after you change your Apple ID or password https://support.apple.com/en-us/HT204071

See If you think your Apple ID has been compromised https://support.apple.com/en-us/HT204145to see what to do.

Increase the Security of your Apple ID https://support.apple.com/en-us/HT201303

FYI: 

See If you see apple.com/bill, itunes.com/bill, or an unfamiliar charge on your statement https://support.apple.com/en-us/HT201382

See Identify legitimate emails from the App Store or iTunes Store https://support.apple.com/en-us/HT201679

For scam related information from Apple including reporting scams to Apple see Avoid phishing emails, fake 'virus' alerts, phony support calls, and other scams https://support.apple.com/en-us/HT204759

See If you think your Apple ID has been compromised https://support.apple.com/en-us/HT204145to see what to do.

Security and your Apple ID https://support.apple.com/en-us/HT201303

iCloud security overview https://support.apple.com/en-us/HT202303

Scam. Apple's iTunes or App Store invoices never, ever, include a link to cancel a purchase. Clicking on the link will take you to a fake site that look's like Apple's, where they hope you'll fill in your personal information.

Delete and ignore.

Hi!

Check this out: If you see apple.com/bill, itunes.com/bill, or an unfamiliar charge on your statement - Apple Support

Has your credit card been charged? Have you contacted the credit card company to check?