Bad Service

Very disappointed with the service I received today at Boxer Lesedi in Vosloorus, they refused to assist me because I was paying with their Boxer Voucher(eCoupon). What is the point of offering this service if your stores are refusing to take it. The Supervisor and assistant manager refused to assist me and were very adamant that these vouchers do not work in their store, whilst Boxer liquor next door recognized it. Your response to this will be highly appreciated because I spent over an hour at the store being humiliated by your employees!!!