Z28 Android Box/ Can't install any Kodi version!!

Hi Everyone.

I have purchased 3 android z28 1g/8g tv boxes.

I can't for the life of me get them to install Kodi 16.2 or any Kodi updates for that matter, during each install I get (the package conflicts with an existing package by the same name) 

The firmware seems to only allow the Kodi 16.1 rc3 I realize that I should uninstall the previous Kodi in order to install the new Kodi 17, but Kodi seems to be part of the firmware. I cant uninstall or disable existing Kodi. This box is unrooted as well, all the previous boxes I have previously purchased have been rooted, is that something to do with my issue trying to uninstall the existing Kodi? I have tried updating firmware to 7.1.2 with no luck, the batch tool tells me that is was updated successfully however after checking it is still 7.1.1   I've tried to change the name of the package and got to the point that Kodi 17 would install however once it's loaded the message is (Kodi has stopped working)

I really need some help here, It has to be something I'm doing wrong. There's no way that these boxes don't allow for Kodi 17 update?

Am I installing the wrong Apk file? I've had numerous android box's and have never had issues with the most menial tasks as to just update Kodi.

PLease lol..... can somebody help me??