CTBC is a regional operator that works in part of the following states:
Minas Gerais,
Goiás,
Mato Grosso do Sul,
São Paulo.
The prepaid plan is :
Você Pré-Pago
The offers are:
Noite - off-peak from 20:00 to 08:00
Comercial - off-peak from 08:00 to 20:00
Fim-de-semana - off peak on Saturdays, Sundays and holidays.
Celular CTBC - reduced rates to call CTBC mobiles
Fixo CTBC - reduced rates to call landline CTBC numbers.
Website:
CTBC - Soluções em Voz, Internet, Comunicação de Dados e Data Center