Sounds like he knew they weren't the correct bolt pattern and hoped you wouldn't realize...
Hopefully you can find a buyer who has a vehicle with the correct bolt pattern for the wheels without the adapters.
Agreed, he pawned his mistake off him. Lesson learned. At least it didn't do damage to your truck.
So, do some hunting here on TYF and confirm the bolt pattern I posted earlier of 6x139.
What's also important is offset. Offset is how far off the mounting surface is, from the centerline of the wheel. That is going to determine how far in, or how far out your wheels are to the edge of the fenders. Keep in mind, the offset can also give you a deeper lip depending on how the manufacturer builds the wheels for different offsets.
It's a balancing act really, you don't want to get TOO close to the fenders on some vehicles because you will bottom out on them if you lower the truck, and you certainly don't want to tuck your wheels in too far bc that looks pretty silly..think potato on toothpicks. I would hunt and hunt, then hunt some more on this site for the look you want. Then buy the exact size, bolt pattern, and offset of those wheels.
You want to check out what offset these guys are running on the 07+ trucks and see what works for them and what you want to do. If you want to eventually lower your truck, check out the stance you want to shoot for.
Good luck
B