Thank you for prompt response.
As per checking subscription details, there 2 plans belong to Volume Licensing agreement. Since I am in Billing support, my knowledge is limit for Volume licensing subscriptions.
However, I can direct you to the support team that is best suited to resolve this issue for you. Please contact Thailand Volume Licensing support at 001 800 441 0231 and +65 6622 1235 or email: vlservp@microsoft.com