Refund of ITC

Our client company is having GSTIN in Delhi and Bangalore dealing in export of services (Recruitment). Invoice is issued from Bangalore only and there is no turnover in Delhi. However, company has claimed nominal amount of ITC of Rs. 15000 approx in Delhi from July 2017 till date. Can we claim refund of this accumulated ITC as there is no supply from Delhi branch? If not, then can we reverse this ITC in current GST return without payment of any interest?