It is seriously twisted logic of concerned Dept's officer to issue SCN u/s 73 / 74 in your situation where there is no wrong availment of any ITC by you.
How can one raise any demand u/s 73 / 74 upon the tax-payer just because ITC as per Form GSTR-2A was greater than ITC actually availed by the tax-payer (and differential amount was towards ineligible ITC).
To my mind, this is pure harassment of the tax-payer .... nothing else. I guess some officers lacks elementary understanding of GST law, despite more than 6 years are passed.
Having said that, the tax-payer got no option but to suffer and defend himself against such SCN by proving the facts & law (i.e. unless and until, he is willing to challenge such perverse SCN itself by filing a writ petition before jurisdictional HC, which can be costly / daunting affair for majority tax-payers)
These are ex facie views of mine and the same should not be construed as professional advice / suggestion.