RATES isn't showing up in our website

We are getting a response message of - "Sorry, we don't support this item category for Australia. (Sport & Leisure)". While all our items is labeled as 'Sports'.

We are passing 10-20 items in the api and I think it's has something to do with the package dimension as there is only a limit for Australia Post but EASYSHIP is NOT SPLITTING it into multiple package when passing to AUPOST. (Note: We are using only AUPOST for our domestic shipment)

In addition to this, the api is giving the wrong error message. Can someone help us with this as no rates are showing when our customer is trying to buy multiple items. I will need an urgent solutions for this ASAP. Thanks in advance.