M&B Birthday voucher expires before expiry date

I was issued with a Birthday voucher for a slice of cake, the app advised that the voucher will expire on the 30th October. However, on the morning of the 30th October, the voucher had already been removed. I had contacted the customer care centre and their response rate is much to be desired. I was told on the 1st November that the voucher will only expire on the 31st October???!!! How can I use a voucher when it expired the day before the email was sent out. Nevertheless, I followed up and advised them that the app advised me that the voucher would expire on the 30th October and it did. I have just received an email after all the back and forth only to advise me that "The code had expired as they state and unfortunately we are unable to re-issue another voucher to their profile. The customer may have to wait till the coming year to qualify for a Birthday Voucher." They are able to issue another voucher, they just don't want to issue another voucher but expect us to continue to support their brand. I think not.