I WON A VOUCHER AT PEP BUT CANT USE IT CAUSE OF THEIR PRINTING ERROR.

I bought a box of Lekker marshmallow eggs at PEP and when I open the box I got a golden card which says I won a PEP voucher worth R1000. The following day I went to PEP to use the voucher, then I was told that their voucher doesn't have an alphabet, then the lady said she need to call head office so that they can reprint the voucher no, then she then came back to tell me that head office will come back to me, but they did not call me back. Then I called PEP head office and they asked me to send the card with the voucher no so that they can rectify it, then I did send to *** that was on the 15th . Then on Tuesday I called I spoke with Tracey and she promised to come back to me and she didn't. All I want is PEP to correct their mistake by printing the correct voucher number so that I can use it, I won it. I now feel that PEP is a **** also, how can you put a voucher with a wrong number and said client won, I feel like this was done on purpose. Is this what you call Customer service?