How can I charge a cellphone carrier company?

I run a web service. I receive payments / donations through paypal and I'm considering mobile payments.

http://www.boku.com/ and paymo do this.

I would like to see if it's beneficial for me to skip the middle man.

Question How can I charge a cellphone carrier company on a particular phone number?

P.S. Any other suggestions on receiving payments?

The reason these "middlemen" exist is that they save you the trouble of doing individual deals with hundreds of carriers all over the world to be able to receive payments from customers no matter where they are located.

You could set up accounts with individual carriers to receive payments, but each deal would only enable the subscribers of a given carrier to make payments to you. Unless you are only interested in customers on a small number of carriers, it makes a ton of sense to use services like Boku or Paymo.