GST excess paid earlier adjustments doubt

Dear frds/ experts,

Case: A Pvt Ltd service oriented company has provided their service to their client for Dec'20 & Jan'21. Hence Inv raised & its Gst also paid by the service provider in the succeeding months. But till now the client had not settled the above payment and the service provider considered this as Bad debts now. In this scenario, Can we able to adjust that excess paid gst during Dec'20 and Jan'21, now ?? If so, then plz let me know the procedures with the provisions....

Thanks in adv/Maya.

Plz treat very urgent...