i have an iphone 6 plus which show iphone disable connect to itunes. i tried to restore but it won't work and everytime it says "Iphone "Iphone" could not be restored because firmware file is corrupted disconnect and try again later"

last night while i was sleeping at somone has tried to open my passcode if Iphone 6 plus model A1524. Now i cannot see the passcode screen and it just saysi phone is disable connect to itunes . Then i decided to restore my iphone and i have download almost 4 firmware files (iPhone7,1_8.3_12F70_Restore.ipsw and iPhone7,1_8.0_12A366_Restore.ipsw and iPhone7,1_8.0.1_12A402_Restore.ipsw and fourth one is iPhone7,1_8.2_12D508_Restore.ipsw.part) and restore (by holding shift in itunes and selecting file ) using itunes ( which is current version 12.1.2.27 64 bit) but for everytime two of them(while extracting ) which are (iPhone7,1_8.3_12F70_Restore.ipsw and iPhone7,1_8.2_12D508_Restore.ipsw.part) it says "Iphone "Iphone" could not be restored becuse firmware file was corrupted please disconnect and try again later" .i have tried to download "iPhone7,1_8.3_12F70_Restore.ipsw " manually and via itunes (when i download and restore using itunes it says

"There was a problem downloading the software for the iPhone ''iPhone'' A unknown error occured (9006).

Make sure your networks settings are correct and your network connection is active, or try again.''

but nothing works (While for rest of two it says firmware file is not compatible).. I'm tired of these now as i'm working on this problem for 5 days 😟...

Please help me as soon as possible..

sorry for my poor english..