Aldi complaint: Cashier refused to accept an Aldi Food Voucher

I visited Aldi on 130821 and presented my food voucher to the cashier to pay for my shopping. The cashier rolled her eyes and said the vouchers were out of date even though they clearly showed the date they were valid from which was July 2021. She refused to take them and would not accept they were in date. She tutted and was very rude and abrupt. I was forced to call a family member who transferred cash into my account so that I could pay for my shopping
I receive these vouchers I am a single low paid parent with 2 young children and the vouchers help me to feed by children during the summer holidays.
I asked to speak to the Manager (Eva) and asked her to refund my card and take the payment with the voucher. She also refused to help and said she did not know how to do this. The experience was very humiliating and as a consequence I have been left without any money and with vouchers I can’t use.