False advertising

You guys are falsely advertising that we can use vouchers to pay our account I have a few vouchers currently and it keep saying its unsuccessful when I try redeem it then when I try again the voucher option is not available huh?, then your AI says you dnt use vouchers..how so why do you have the option? And I have used vouchers before and made payment why is this one so difficult? haai no this is actually nonsense I have been out of internet the whole week fighting this We can sue you for false advertising do you use vouchers or not?