Urgently need to contact Sage One Accounting's Management

We have been experiencing problems to import 1 of our biggest clients’ 2020 & 2021’s GL in Sage One Accounting, into CaseWare, since January 2021 already. This was originally a Pastel client, before converting to Sage One. It used to work well until Sage One was down for weeks in January 2021. Despite some feedback from “The Accounting API Team”, the issue has not yet been fixed. This resulted in the client’s audit not yet being finalised; being unable to produce proper monthly management accounts; and with its bankers about to terminate all finance facilities due to the delay with audited AFS and up to date management accounts. Sage One Accounting ignores our pleas for urgent assistance to resolve the matter. Besides the client wanting to change accountants, legal action will be instituted if the delay to produce up to date financial records, required for the extension of facilities with the banks, result in the company having to close its doors. How do we get hold of management, as this needs to be resolved in the next 24 hours!?