Whatsapp Billing/ Pay per message

Hi I am trying to find a software which offer pay per message for the Adult and Psychic category

I want to be able to charge my customers per message

So when a customer goes to my website they see the profile of the Psychic reader they want

They pay and then get redirected to either Whatsapp etc.

You'll most probably have to get a custom webapp built for this. However, if you want to charge your customer per Whatsapp message, it might get a little tricky.