Factory reset Mikona 7" tablet
It sounds like he started a reset and you turned it off when doing so.
Turn it on and if it boots up go into settings back up resart/reset go to the last 1 on the list it will reboot into boso. Useing the home button to go down the list to clean and reset use the power to enter it will then resart ur tablet if u can not do this a phone shop shoud be able to help reboot it for u hope this help