If you have an active plan and purchase another one, only the resources of the same type will accumulate and extend their validity. The expiration date will be adjusted according to the most recently purchased plan. For example, if you have a plan that includes DATA, VOICE, and SMS, and you purchase a voice-only plan, the minutes will be added and extended, while the data and text messaging will retain their original expiration date.

Remember that the Daily Plan, the ToDo Plan, and the National Navigation Voucher do not accumulate or extend their validity due to their specific characteristics.

Data will be discountded in the following priority order  :
Daily Plan
ToDus Plan
National Navigation Voucher
International Bonus
Data from the purchased plan
Consumption fee (if active)

The 50% discount only applies to data usage, not calls. In order to make calls at a reduced rate during these hours, you need to have main balance.

No. The minutes and SMS of the plans in national currency only allow national traffic. For international traffic, you must purchase a plan with rates in USD.

No, it's completely free to remove numbers from the Friends Plan. You can do it by dialing *133#, option 4 Friends Plan, option 2: Add/Remove numbers.

To change a number, first delete the existing number and then register a new one. You can do this through Online Services or by dialing *133#, option 4 (Friends Plan), and then option 2 (Add/Remove Numbers).
 

If you decide not to continue with the Friends Plan, you can deactivate it at any time by dialing *133# option 4: Friends Plan, option 1: Activate/Deactivate Plan or by going to Online Services.