Well, it's not as if you bought a new Ferrari 296 GTB and you weren't satisfied with its performance and returned it, only to find it parked in your driveway with the keys in the driver's seat the next afternoon.
Perhaps, you can create a new thread and troubleshoot your issue. If you get the game working by adjusting your settings based on your input, then you can let GOG know and play your game happily. If you decide to create a thread for help, do include your PC's specs, Operating System, and a more detailed accounting of your issue(s).
For example, if you have a NVIDIA GPU, adjusting the Control Panel settings for a specific game can work "miracles."