I've been getting unsolicited calls from the 858 area code and from 858-752-6473. I did not pick up the call and put them on my blocked list on my HTC one S mobile. If you have this model of phone or a similar HTC droid phone here instructions to block numbers...
Here is the link and the link - http://support.t-mobile.com/docs/DOC-4248
Block calls
To block incoming calls from specific contacts or remove those contacts from the block list, follow these steps:
From any Home screen, tap the Applications applications icon.png icon.
Tap Contacts.
Tap Manage contacts.
Tap Blocked callers.
Make the desired changes to the list:
To blockcontacts, tap Add. You can Select from people or Add number.
To remove contacts in the list already, tap Menu, Remove callers, select the check boxes for the callers, and tap Delete.
To manage contacts and change names/numbers, tap the contact in the list.
Press Back when finished.