Ring Protect Plus Annual Discount

Hi! I just signed up with Ring Protect Plus and the plan option states $20 savings for annual subscription. However, I was charged $100 when I expected $80 for the annual subscription. I called the customer service line and was told no, I don't get a $20 discount but 10% off if I purchase further ring products. I was looking at the screen when talking to the agent and no where do I see anything about that for signing up. Where is the $20 credit and this looks like false advertising. Someone please let me know. Thanks!