How to change Properitorship trade name in GST registration?

You can amend the details...... once the amendment process starts in the system. You CA is not totally wrong....

Currently change of Trade Name provision not availabe. This option may be implemented soon from the end of this month or in next month. May ask at GST Helpdesk 0120 4888999

At Present, the change of Trade Name option unavailable, this option may be implementated at the end of this month or next month. You may contact for further clarification at GST Helpdesk 0120 4888999