How do you call back received phone calls from your area code that are invalid phone numbers like 509 011 947 and 509 011 918 for example?

You can't call back to those numbers, which is the point.

Unfortunately, it is very easy to "accidentally misconfigure" (cough, cough) a PBX (private telephone switch for a business) to send invalid data for Caller ID. Thus, many telemarketers and other annoying callers send gibberish.