REFUND APPLICATION

I deal in jewellery,
tax rate on sales is 3%, tax rate on my input goods is 3% too, but I am paying 18% GST on Rent, CA services, billing software and on many services. Because of this ITC is being accumulated in my credit ledger.

How do I claim refund of this ITC?
refund application under inverted rate supply category can be filled only if GST rate on input "goods" is higher than the rate which supposed to be collected on sales.
Where as my accumulation is due to what I am paying on input "services".