1. As far as your phone goes, there Apps that you can download on your phone. For example, on my Droid MAXX I have the following Apps installed Calls Blacklist and Contacts CallApp . Both Apps have Blocking Features. Yet, one thing that some people do not like with these Apps is that you have to add the Unwanted Call Caller as a Contact on your phone's address book. But what I have done is to have a couple of Contact Entries set-up on my phone. Then I just add the Unwanted Call Caller's phone number to one of these Contact Entries set aside just for that purpose. However, I am not sure if these Apps are available for your iPhone. Yet there should be similar Apps available for your iPhone.
2. Something else you can do is complaint to the FTC.gov in various ways. If you are on the Do Not Call list for over a month or so, you can file a complaint at https://complaints.donotcall.gov/complaintcheck.aspx or https://ftccomplaintassistant.gov/information#crnt&panel1-1. Also you can forward your Unwanted Spam E-mails to email@example.com. Furthermore, you cam forward your Unwanted Spam Text messages to 7726 (SPAM).