Top-ups can be made directly at their offices or through the online application they have...their address is on the web.
If you have the application on your mobile, on the home page there is a button with the + sign, to the right of the box: Your Pocket, you click and you get several offers to mark the amount of money you want to use for a given call time, you may not use it in full and you can use it in another call later, then select the contact in the same application you want to talk to and wait for the call to connect. Greetings and luck.
Go to the office of Cubamas in an office that stays close to you ok
Thanks! Your answer is awaiting moderation.