Help!! Left stranded by global blue

Has anyone successfully contacted Global Blue recently regarding a VAT refund problem?
My refund appears to have been issued to the wrong credit card, possibly due to an error at the retailer. I’ve tried the official support form, phone numbers, and chat support but have received no response.
Does anyone know:
a working contact method,
an escalation email,
or what finally worked for you?
I have all transaction references and documentation.