You need to email NGPVan directly. Tell them you want off all of their systems. They will say they don’t have a way to do this. You then reply that they are lyi

You need to email NGPVan directly. Tell them you want off all of their systems. They will say they don’t have a way to do this. You then reply that they are lying. You can also threaten to contact the FCC (a bluff given political spam is exempted from so much). They will then remove you.