Hello - I'm new to this forum and could really use some help!

We've just bought a Davinci Jnr 1.0. The only thing we can print is the demo file from the SD card because I can't find any files on XYZPrinting web site that actually work.
For example I copied the Eiffel Tower to the SD card (because it had the same file extension as the demo so I assumed was compaitible) but it just says invalid file when I select it on the printer.

I have tried countless times to ring XYZ and emailed them but I get cut off everytime on the phone and get no response to emails?

I just want to print something other than the demo !!

Any help much appreciated.

Thanks you.