..LucilleBa11..
Perhaps on the 'retail side' of an incoming call, you may not
be able to block each one; I know I can't. Even with landline.
Some of those might still be scam or phishing types of calls.
There are support articles with different views or instructions
on how to try and deal with those. Some are like you've tried.
Detect and block spam phone calls - Apple Support
//support.apple.com/en-us/HT207099
Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support
//support.apple.com/en-us/HT204759
Avoid unwanted calls on iPhone - Apple Support
//support.apple.com/guide/iphone/avoid-unwanted-calls..
(send unknowns to voicemail; see for more detail)
Get help with security issues - Apple Support
//support.apple.com/en-us/HT201221
[Hard to compare what you may have tried to hopeful results.]