I bought premium but it wont let me use best in bag
Have you tried logging out and back in again? Sometimes that can resolve issues like this. If it doesn’t, contact us via our contact form (Support - Ask Mr. Robot Account and Billing section) and we can look up your account info and get everything straightened out.
Is the cost for TBC premium $10 + $12?
Yes, it’s a $10 one-time payment to add it on to your $12 annual subscription. You’ll never pay the $10 again, but you do have to pay the $12 each year to keep using the site.