Birthday voucher still not working

I’ve received a birthday voucher from TFG but I’m unable to use it. I’ve gone to numerous shops trying to redeem the voucher & ive tried to use it online with no joy. I know it’s a gift voucher but I just feel like a fool going to all the shops & trying to use the voucher. The shop assistant said my details on the system are not correct, it doesn’t match my ID . I’ve sent them an email, but I think they’re tired of hearing about this birthday voucher. I’ve always received a good response from them, just feeling let down now. I’ve tried using it online as well, but I’ve lost interest now after all these attempts.