unchecking a verified caller

There is a spam phone number with a checkmark (call that has been verified by the carrier), which I keep blocking, but I keep getting phone calls from that number. Is there a way to "reverse" the verified by the carrier label? I think that is why I am continuing to get these calls. I am unable to manually add this number to my "Blocked Contacts" list via Settings because the number is not in my contacts list (it's just a random number that keeps calling me to tell me about Medicare). This company tricked me - said I could opt out by hitting 1 and I think that actually opted me in with the verified number.