Customer service pathetic regarding gift cards

I am an Edgars club member of the past 25 years, a week ago I won a voucher, I called customer service and spoke to Liz on the 11th Feb, to query whether I could change the voucher for smaller denomination, I was told YES, to come in, I went in today, the 20th Feb! I advised the cashier, who did not seem to know what denomination was!! She Called Pearl, who asked where I got the voucher from, I told her what I wanted, she transferred the entire amount to another card, she confirmed it was in error, she then called Liz, as she had no idea what to do, Liz firstly could not remember my call, she then insisted she told me it cannot be done!! I told her all my calls at the office was recorded, to which she responded she asked me to come in for assistance, I was told I can leave & wait for Monday, whereby the vouchers will be emailed to me, despite me spending 15minutes already!! This is pathetic and disgusting service, they were more concerned as to where I got the voucher, then to add insult to injury, when I ask for the amount to be transferred back to my card, Pearl squashes th card behind the counter, I spend thousands each year and get this!!!