Read the terms before you reply
Check what the agreement says about unused time, notice and refunds. Reply from the contract, not from feeling.
Show what was delivered
List the hours or deliverables used. A clear summary often changes the conversation.
Separate used from unused
Refund or credit what is unused if your terms allow it, and explain how you worked it out.
Ask what went wrong
Invite the client to say what fell short. It may reveal a fixable problem and saves the relationship.
Offer options
A credit, a reduced scope or a pause may suit them better than a full refund.
Confirm the outcome in writing
State the amount, the date and that the matter is settled. Close the loop clearly.