Refusal to accept valid gift voucher

Good Day

My daughter received a egift voucher which expires on 9th January 2023 (Next year). It states on the voucher she can use at any CNA, Edgars, Boardmans etc

She went to use today only to be told by CNA and Edgars that it is invalid

THIS IS COMPLETELY UNACCEPTABLE.

HER VOUCHER IS VALID

Please advise immediately

Kind Regards

Angela