No SoftLayer API to cancel storage type of products on anniversary date

[mnnmountain]

There're following methods on SoftLayer_B
cancelService
cancelServiceOnAnniversaryDate
cancelItem -> with option to cancel immediately or cancel on anniversary date

For Storage types of product, (e.g Endurance Storage), only cancelService() methods can be used. API gives an error when using cancelServiceOnAnniversaryDate or cancelItem

Can you please provide the API to allow cancel storage product on anniversary date?

Thanks.