Cancel the invoice

Dear Sir,

if we raise service commision invoice to delhi party our business in up & also deposite the tax against this invoice & also set off the liabilty but we want to cancel the invoice bcoz party refuse to pay the amount & break the contract by verbally.

1. how to cancel the invoice under gst regime & its impact.

2. how to get tax back which we already deposite.

3. it's possible after submit the gstr1 & gstr2 & gstr3b.

4.how to we can rectify bcoz party refuse the all payment even break the contract verbally not in return we have no documents with him.