You really never any intimation of maintenance. you cant relay on this for any transactions. For every 2days it will not work. Their customer service people knows one method to test the connectivity. when ever you call they will tell you the same procedure which will never work.
The worst thing is if you lost internet at 5PM then CC will say that they will do it tomorrow only. if you call customer care you need to wait minimum 10 mins for them to attend call. I hate it so much. changing my location for better internet.