Wrongful DMCA Takedown Notice

[LPPonMain]

Our website was taken down after being reassured by Shopify support that it would not be. I have all the documentation showing that they took our payment for a theme. We were later refunded for the theme without any notification or request to do so. I can not repurchase the theme because we already own it. A response for shopify legal said we needed to take no further action and our site would not be taken down. A few days later our site was taken down and we are still being charged for shopify's service. I have gotten nowhere with the chat support, saying that the issue will be handled and the ticket has been escalated. I sent them the invoice for the theme we purchased to which they responded, "For assistance with obtaining a manual invoice from our billing team, please contact Shopify support" which I did and was sent back into this endless loop. Each time the ticket is closed without any kind of response. At what point do I file a complaint with the Better Business Bureau and is this grounds for legal action?