Direct Operator Billing (WAP Billing/1-click-flow, 2 click flow, ussd flow MSISDN) Payment Integration Vas mobile subscription

I am searching a freelance who can integrate a payment gateway by mobile phone credit billing (Direct Operator Billing/WAP billing/MSISDN) to a landing page. In detail: >> The landing page it's ready: there is a button with call-to-action “buy now”. >> The price must be charged on user's mobile credit when him clicks on this button: then the user must be instantly redirect to the page with the digital product. All the process must be instant (1-click-flow): the user clicks on the button, his mobile credit must be immediatly charged, and he must be immediatly redirect to the digital product's page. Everything without other actions, step or interruption. * The landing page is not directed to some specific country, so the freelancer must suggest me the best countries to do this and the payment integration must be done considering the principal national telecommunications operators. The freelance, in particular, must: - Choose the company that provides this type of service (if necessary). The limit are that this provider have a control panel (for payments monitoring) and that haven't a fixed price (must have the price in relation to payments volume). - This company must provides the telecommunication operators' APIs (some of these companies are intermediaries between the developers and the telecommunications operators).