Why can't I decline a call from home screen? (I don't want voicemail from these callers either.)

If you decline the call, it will just go to VM right away. The only way to do what you want is to answer and then immediately hangup - cuts them off without going to VM.

You can then add that number to your blocked caller contacts, but you cannot block someone pre-emptively. They have to call once so your phone captures the callerID to allow you to put them in the blocked calls list.

And, file complaints at the DNC center when these people call you.

Pressing the sleep button once will send the call to voicemail. If you press it twice (quickly) it will hang up the call and they will hear a dial tone.

Depends on where you are how that works. See the iOS 10 iPhone manual, page 121:

“Decline a call and send it directly to voicemail. Do one of the following:

Press the Sleep/Wake button twice quickly.

Press and hold the center button on your headset for about two seconds. Two low beeps confirm that the call was declined.

Tap Decline (if iPhone is awake when the call comes in).

Note: In some areas, declined calls are disconnected without being sent to voicemail.”

Excerpt From: Apple Inc. “iPhone User Guide for iOS 10.” iBooks. https://itun.es/us/o_ZOdb.l

I know for me, on AT&T in the USA, tapping the sleep button twice just dumps the caller immediately to my VM.

However, most of the unsolicited calls I get never leave a VM message anyway, so I just go ahead and decline or ignore it, then go in and add them to the blocked caller list, and delete that call log entry.

dilbert41 wrote:

Pressing the sleep button once will send the call to voicemail. If you press it twice (quickly) it will hang up the call and they will hear a dial tone.

This is not correct. Pressing the sleep button once silences the ringing, but does not reject the call. Pressing it twice rejects it and sends it to voice mail.

If you're on iOS 10, I have good news for you.

Download the Hiya or Mr. Number app and enable call protection.

Block every category (spammers/scammers/etc.) and your phone will be so quiet you'll think the battery died.

For everything else, submit your ideas to Apple.com/feedback

Report the calls to your carrier, and to the FCC and FTC. There's isn't much you can do about it at the moment. The carriers now have the legal right to set up services that will block these scam calls. 99.99% of the time, the phone number reported by caller ID doesn't even exist.

The only reliable way to block these calls would be for the carriers to compare the originating number to a list of valid phone numbers from all carriers, and black-hole anything that didn't match a valid originating number... even that won't work if the scammers are spoofing legitimate numbers. I once got a scam call where the caller ID indicated the originating number as mine...

It doesn't matter what kind of phone you have or who your carrier is, this is going to be a problem.

I did see an article in one of the tech rags a while ago about an app that is supposed to be available this fall that promises to be able to filter and block these scam calls on iOS 10. Apparently, it can do this without routing the calls through a 3rd party first as all of the others seem to do and it does not have to add tens of thousands of numbers to your contacts, then block them.

I signed up for "early access" notification, but have heard nothing else since. They did provide a referral link to tell your friends. If you have a "throw away" email address you want to give them (I always use a throw away for this kind of thing), it might be worth checking out... If it ever gets out of the vapor ware stage...

https://callblockapp.com/?code=wxW