ERROR: Product type cannot be changed for Items having transactions.

ERROR: Product type cannot be changed for Items having transactions.

I have mistakenly added a product type as goods for an item that was a digital service. Now when HSN/SAC became mandatory, this brought my attention to this error I did.

So I tried changing the product type but it displayed this error message
  1. Product type cannot be changed for Items having transactions.
So next I tried to edit/delete the previous transactions with the same item.
  1. Transaction that has been filed or pushed in GST Return cannot be edited. However, a pushed transaction can be marked as Void.
  2. Items which are a part of other transactions cannot be deleted. Instead, mark them as inactive.​
How to overcome this error? How can i edit the item?

Note: I never push any GST filing details from Zoho. I do them manually referring to the figures from Zoho's GST Reports.