Rcm paid by buyer and supplier

Hello, we providing locker services to banks, as a service provider there is issue in one bank regarding rcm.

Bank will pay GST as per invoice nd that thing we know recently nd otherside we have also paid tax for invoices, we have tried to convince bank to refund tax money but they denied

Now in this case when both parties have paid tax then how can we get refund money

Is there is any possible way?