For anyone using the Mexican provider's Telcel Amigo phone
and data "pay as you go" plan. They've made it nearly impossible to refill your account via foreign credit card. Telcel now requires, in the middle of a refill transaction, a little game
to be played. The client confirms the transaction and is then informed Telcel will charge their credit card some trifling amount (a fraction of a peso). The client is then instructed to phone
their bank and ask for the exact transaction amount and enter that number in a web form. If you don't do it, for instance: if your only form of communication happens to be the Amigo data plan you are trying to refill, or your home cellphone which won't connect to the Telcel system, your credit card is blocked. The only solution is to find a Telcel office and refill your account in person.