Android storage problem
In most android devices this insufficient storage issue is to do with Log files being dumped in the /data/log folder. The log files appear to be the logdump for the gsm radio, and can take up a lot of space over time (Gigabytes even).

Most phones without root have a workaround to delete the logs by dialing *#9900# from the phones dial pad. If your phone supports this then the moment you finish entering the 2nd hash, a menu will open up (point is: if it doesnt support nothing happens; pressing the call button wont help). In the menu that opens, select "delete dumpstate/logcat". That will free up all the space occupied by those logs.

Do let me know if any of you with a A116 is lucky to have this workaround. I have an A116 with the same problem, and am not able to find a solution.