If you have no other global admins on your tenant, then you need to open a support case. The support agent will have yosend the care over to the DPT team. You will have to wait on the DPT team to contact you. You cannot contact them. You cannot send another email, or open a new case. There is not a single thing you can do to make the process faster, you have to wait.
Default wait time is 5-7 day. They can contact you within the hour, or if it takes 30 days before they contact you, then it t will take 30 days.