This is SSI Survey Sampling, a marketing research company.
Keep in mind that if they do not place you on their internal DNC list, they can still get into trouble. As a rule, survey's are exempt from the DNC though. Some states have different laws in regards to the calls, which can differ from the federal but as far as I know, Oregon is the only one that does not allow Charity calls.
Do consider maybe getting a call blocking device or phone.. You can google them and many are around $40.00 or less. If its a cell phone, some already have call blocking, if not, there are free apps on the web that will work for some. You can google this. If you have a smart phone, there is a free app called call control. Iphones appear to have apps also. Another one is called Mr. Number.
Report your callers here if they continue to call and harass: