Saying no without losing the customer

Most support damage comes from vague answers, not from unwelcome ones.

Say it in the first line

Burying a refusal in the third paragraph reads as evasion and forces another exchange.

Give the reason once

One clear sentence. Over-explaining sounds defensive and invites negotiation of each point.

Offer the nearest possible yes

What you can do, what it would cost, or when it might change. A refusal with an alternative is a service; a refusal alone is a wall.