What are the pay-per-response ticket systems?

Question

CRM

The info portal needs a ticket system, you ask a question, you get an answer after payment.
I will describe what it is and why it is needed:
For example, the user needs to find some information in the city where to buy such a product and where it is cheaper.
He creates a ticket.
The operator prepares a response and sends him an invoice for payment (via SMS (from a mobile account) or e-money).
After payment, the user has access to the content he needs.
I don’t even know how to do all this ... I
thought to use short numbers for SMS, BUT registering a short number is 10 thousand rubles + 1000 rubles every month + commission from SMS (information from gsm info)
It is planned to use the functionality both from PC and mobile
Added
What would you advise to provide an account. for example: your answer has been prepared, to receive a response, send an answer to number 1111, the price of the answer is 40 r, or use the link to pay through the wallet
.

Answer 1

Take any open ticket system and attach payment to it.
In general, if you regret 10 thousand for registering a number, then how will you give high-quality answers to me I wonder))

Answer 2

as much as 10 thousand rubles!!!