Absconded from company

Hi, I absconded from company due to personal problem when I was on notice period (20 days left). I left laptop in company guest house before leaving. After a month now I got letter from employer about this, "there is lot of irreparable damages that you have caused to the image of the organization and also jeopardized organization’s relationship with the client. Our Company will not tolerate any such unprofessionalism and lack of judgment, You are hereby notified that if you do not respond to this letter with justification to your action within 7 working days from the date of receipt of this letter, company will take legal actions against you to protect the interest of the company and to recover losses" In offer they have only mentioned below thing, You will be governed by the company policies at any point of time. The company policies may be updated or changed from time to time and you will be bound by company policies. The policies are updated on the portal. Nothing else is mentioned except salary break-up. What can happen if I will not reply to this mail