Mithi has a central customer care number to make it easy when you need to speak with our engineers. You don't need to have different contacts for various activities. Contact can happen through a central point.
Having said that, if you want assistance beyond L1 it can be scheduled on a request basis.
You can mention the same on the ticket or call and the meeting can be scheduled with L2/L3 team.
Please refer to the below link for more details:
Hope this works for you.