Invalid voucher nr from KFC

So finally I was given a voucher nr after struggling for months to get a refund. Then when the moment I added the voucher nr a message poed up to say the can not deliver and must try in 15 min. We'll I tried for an hour and a half . Well that was last week.

I tried again over the weekend but still the same message popped up.

I decided to order today but now I will go and pick it up only to get the message that my voucher nrbis invalid.

Wow KFC this is awesome customer service........first struggling for months to get a refund after send countless emails even phoning your head office only to get a invalid voucher nr.....