Hi, I am an 18+ subscriber paying with a credit card, and I still have no option for open chat.
Here's a copy from one of my posts.
It doesn't matter that you turned 18 in real life, what really matters is when you made your account, and what age you put on it. For example, if you made an account on February 25, 2017 and you put the age as 15, then you would have to wait until February 25, 2020 to enable open chat, when your account would then be 18 years old. I suggest you look at when you made your account, and try to recall what age you put down on it. If you don't remember, I suggest emailing Kingsisle. If the option for open chat is not listed under the account options area, then you still have to wait. Buying a membership/crowns will not make it show up if you still have to wait.
HOWEVER, if you originally put down your age as 12 or younger when you made your account, then that account will NEVER get open chat. The US government makes it illegal for Kingsisle to store your age if you are 12 or younger, so there is basically no age even stored on your account when you first made it if you put one of those ages in originally.
If you put the age as at least 13, then it is simply a matter of waiting.