letv le 2 x620

heloo.i need help.i bought leeco le 2 x620 and after few days i trayd to instal ofical 5.8.15s rom.but when i instal it my phone bricked and stuck on letv logo and does not go any further.recovery crushed down and now i can not enter it.i can enter only fastboot mode.i trayed to flash rom by sp flash tool but it does not recodnise my phone and do not want to instal rom.can you please help me.i tried to put rom true fastbootmode it doesnot work either.please help me