Well, there is really only one more thing to do to really get anywhere here. With your original stated numbers, I maintain that your vehicle would have had to use 600Wh/mile average over your stated 50 miles. This would only allow you to be able to drive approximately 88 miles on a full battery. So, I would say the next step would be to charge your car to 100% and plan a drive of at least 44 miles with no stops, on the highway, no putting the car in park, no heat, no A/C, and no going over lets say 70mph max(preferable no more than 60-65).
After those 44 miles if your battery is at 50% then I say you have a bad battery and go make a service center appointment and tell them to look at the car data for that drive. Tell them the date and time of the drive and they can look at their data.
If your drive only puts you at about 80%, then all is well with your car....and your issue must be explained by your specific non driving usage.
I think this is as simple as doing a 44mile drive and it will give you all the data required. 50% usage over 44 miles of straight highway driving is a bad battery I think no matter how you cut it. I don't think you can drive 44 miles at 600Wh/mile legitimately without either getting pulled over for speeding, or crashing and killing yourself.
Do the 44 mile drive and then come back and let us know what happened.