If the actual door frame opening is not as wide as what they say, you have more of a moral right to keep pushing, than if it is a situation like the way the door is hinged causing the effective opening to be less.
In 20/20 hindsight, of course, you would have measured that door before putting anything else together, if it were not possible to measure it in the store display.
Unless you are in a terrible pinch, it might minimize your headaches if you just sell the shed, then get a more suitable one from someone else, expand the foundation to install it, and don’t look back. Depending on where you are, there could be Lowes, Menards, and other hardware/home improvement stores.
Yeah, the opening without the doors on is about 2 inches narrower than what is advertised. I believe this is info coming from the manufacturer, so HD would be able to go back to them and recoup any loss.
We talked about selling it, but there’s still the problem of disassembly and transport.