Small e-com: piling up ITC from ads—any way to claim refund?

We sell garments under ₹1,000, so output GST is 5%. We pay 18% GST on Meta/Google ads and ~30–40% of our cost is marketing, so ITC on services keeps piling up.

Our CA says inverted-duty refunds are only for input goods, not services, so ad-GST can’t be refunded for domestic sales.

Is my CA right or wrong? If refunds on ad-GST are possible, how do I do it (which rule/form)?