I'm unsure how C4D works in terms of acquiring the trial, but I'm almost certain you can cancel your trial and remove the card before the 42 days end. I've seen multiple products use that method in hopes of people somehow forgetting they linked their card / or end up buying it cause they're too lazy to go through the process of unlinking their card. Worse comes to worse, you can call up your credit card company to sort of chargeback the $2000.
Besides, you could of gotten C4D for free had you just done a youtube search for "How to get Cinema 4d for free".