8th February 2017 From India, Kolkata
They do not need to confirm you, it's a choice lying entirely with them
In general comaonies frown on leaves during probation and definitely don't like unscheduled and unapproved leave. It is natural that the Company will therefore be unhappy. It is generally considered that if an employee does not behave properly during probation, it's unlikely to be a good employee during confirmed / permanent status.
Sending out just an SMS during absence, not even calling and telling the manager you have a problem is generally considered unacceptable
If they decide to terminate there is very little you can do
I suggest you go and apologise to your manager and explain the situation
13th February 2017 From India, Mumbai