MTN Yello Bucks Voucher ****

As all MTN users know, we now get yello bucks to spend on vouchers to use at various vendors, I recently bought a medirite voucher and went to a medirite pharmacy this weekend. When wanting to pay with my voucher the pharmacy told me they dont accept thse vouchers as it is a ****. They printed me an email from a manager at Checkers, saying that the whole MTN voucher thing is a **** and that they have no partnership with MTN, I cant believe I was *****ed by MTN with these vouchers. Everyday I get a sms to use my points, this is a ********** thing, Unbeleivable