Selling **** goods

I bought 2x vouchers for discount on travelstart domestic flights only to find that they are not working. Once you buy the voucher, they send you a code that you can insert on Travelstart in order to receive a discount on flights. None of these vouchers work. It is such a pity as they advertised these vouchers for the Black Friday Sale. This is not my first bad experience with hyperli as this problem occured before but thought it would be different this time as they advertised it on their site again, giving me the impression that it is working. Selling goods that are **** is highly unacceptable and unprofessional. I don’t trust this site and won’t recommend anyone to do so.