@asmfsdfmglkmfsl did you select "Change plan now" and did it charge you $35 ?
if you select "Change on renewal date", it is known that it will show your next bill to be $55 without the $20 discount.
Just a reminder, this promotion is supposed to be for new activation only, we still not sure if it is a glitch that exiting user can choose , so change plan as your own risk 🙂