How to change the ban on sending paid SMS to a specific number?

Question

Android

I have a phone with Android 6. When sending SMS to a paid number using a regular SMS client, I accidentally prohibited sending SMS to a certain short number. Now, when sending SMS to this number, it says "failure". SMS is successfully sent to other paid numbers. Through another SMS client (hangouts), SMS is sent to the problem number.
I tried to clear the data and cache through the application manager with a regular SMS client, the problem was not solved.
Where can I find the settings for sending SMS to paid numbers from a regular client? How can I change/reset them?