I am happy to assist you tspitts!
The call you received appears to be an International number. You can view the details of your calls by signing into your My Verizon account online at www.verizonwireless.com.You can check your unbilled usage details, such as calls, text and data as well as previously billed calls.
I trust I have answered your question.
Anthony is correct. It is a call from El Salvador. 503 is their country code and they have 8 digit phone numbers.