Digital bank that doesn't have flexibility and customer service

I made a payment via my card to booking.com which i cancelled and they refunded me. Its been 15 days but no funds in my account. Ive called Customer Services numerous times to only get excuses. Apparently funds have been in the suspense account and theres a backlog at the card division. So when will i receive my money and this query be resolved. I need this to be sorted out asap please. The service is unacceptable.