Poor customer service and false information

I went to checkers to use a voucher on the 18th October and was told that i should use it for airtime as the system is refusing to take it i went on the 19th and they could not use the voucher , the lady went to inquire at money market as the voucher was from money market app and she was told that it will be active only after 2 weeks i told the cashier that am not going anywhere until the voucher is used and the cashier tried it again and it was successful i have the fact that they are giving customers false information on the 29 i had a another voucher for checkers liquor and the cashier told me the voucher is declining and i should go inside the store to do a gift voucher when i got there i was asked how much is the amount and i was told gift cards are offline because of the amount i have for my voucher i was not helped checkers centurion customer service is poor!