Missing about 30 refunds from Amazon

I have the metal card and i am supposed to get customer support., but its been 6 months that I am running after refunds that I was supposed to get to my HSBC. card.All the refunds are from Amazon and collectively about 2000 GBP . I have contacted customer support by app, by email as well as twitter … its been 6 months now without a resolution in sight !.. do I need to escalate this further ?