Apply for leave (in writing only) and wait for their action.
Check www.labourlawhub.com for more information on labour law.
You have been absent for 2 days only, and they have sent you an absconding letter.
That is surprising in its self, unless the company has a policy of sending this automatically.
I assume you did not bother to inform the company of your illness.
I also assume that you are a senior management employee as you said operations management.
I find it surprising that a person at senior position didn't bother to call and report sick and that no one from office called to ask what happened. There is more to the story than meets the eye.
You have been sick for 2 days, your salary is on hold till you join back. So what exactly is the problem ? You will join back in time right ? Salary date is next week. Or are you planning not to join ?
I am working as a training manager (L&D) in a BPO myself.
But, you can always get back with a medical certificate if you are sick is the key.
Normally, salary is never kept on hold, but you do not know.
Two letters of warning might be sent to your current address asking you to report back at the earliest.
However, report back at the earliest before they raise an abandon.