True smart 4G speedy 4.0'' plus

[MauroR]

Hello, some of you bought in Thaland a  phone True Smart Speedy 4G 4.0 .I bought one and by doing an update it went haywire..then, slyly, I thought of doing a factory reset without making any backups????.Well now the problem is that the phone continues to turn on and off indefinitely.  Someone would have the same phone to tell me how to get it started again.

Thanks for any advice