611. Please be assured that there’s no quality problem with our products.
612. I promise you our price is the lowest.
613. I apologize to you for our carelessness.
614. I am afraid we cannot accept your claim.
615. I’m sorry, it’s a misunderstanding.
616. Sorry, it’s our responsibility.
617. I’ll send a repairman up to you.
618. We just prepare it in according with the contract.
619. Let me do it for you.
620. Sorry to interrupt you for our carelessness.