Then call Choice Customer Service yourself, tell them you have the email confirmation which shows the booking was a king bed, and ask them if you want them to have you forward them that confirmation. At the very least Choice Customer Service needs to realize that the hotel lied to them about the booking having always been for a queen bed.

Ie, I don't know if Choice can or can't help you with getting your original room type at your original rate restored, but at the very least Choice should look into whether this hotel is voilating their franchise rules, which it might be if it's arbitrarily changing room types on customers and then lying about it to Choice central.

This might be a situation where you'll have to talk to a Supervisor, and they may have to contact the hotel, so if you can try to call when you have time for an extended call but also when the manager at the hotel is likely to be on duty.

(I presume the original rate for the king bed that you booked is no longer around, or else you could cancel and rebook and see if they pull the same trick again, but this time have Choice be on the look for it ahead of time, ie tracking any changes to your reservation and where they come from.)

By the way, do you have any status at Choice?