Hello Valleygirl2023,
Thank you for using Apple Support Communities. Sounds like you're experiencing issues with unwanted calls appearing on your device. We also notice that you're already coming from the following resource below:
Detect and block spam phone calls - Apple Support
This is a great resource to review for help in blocking spam calls. If that resource isn't helping, you can try to manually block that number as well. The following resource can show you how to accomplish this task: Block phone numbers, contacts, and emails on your iPhone or iPad - Apple Support
From the Phone app, tap Recents, then tap the Info button 
next to the phone number or contact that you want to block. Scroll down, then tap Block this Caller.
You also mentioned that this number is showing up in your Recent calls list. This doesn't sound like expected behavior. You might want to consider installing the latest iOS update. The newest updates include various security updates to keep your device safe and secure. Just in case you do have pending updates, you can use this link to guide you through the update process: Update your iPhone or iPad - Apple Support
1.) Back up your device using iCloud or your computer.
2.) Plug your device into power and connect to the internet with Wi-Fi.
3.) Go to Settings > General, then tap Software Update.
4.) If you see more than one software update option available, choose the one that you want to install.
5.) Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do.
Your carrier can also help you block specific phone numbers as well. You might want to try reaching out to them for assistance. Lastly, if your feel that you want to better secure your Apple ID, this resource can also help you: Security and your Apple ID - Apple Support
We hope this information is helpful. Cheers.
