How to organize the disconnection of the WiFi session after the time or traffic packet has elapsed?

Question

Network administration

Good day.
Please tell me, as a person who is friendly with IT, but far from System Administration, about how the following system can be organized in a small hotel (hostel) with minimal blood loss:
1. A person buys a package of time and traffic to connect to WiFi.
2. Connects, uses and after the first or second connection is cut off and you need to purchase the service again.
3. Tech. staff has unlimited access from any device (well, or, in extreme cases, from certain devices)
Thanks for the answers.
PS Who cares why limit traffic: we live in Kamchatka. Unlimited Internet barely pulls out the loading of the VKontakte page, and any faster connection is always paid.

Answer 1

Dig towards The Hot Spot in a Box
In short: The client pays for a certain Internet time, the admin gives him a login: pass, the client connects to wifi, authorization by login and password goes through the web.