Ebay: Received False Goods - What to do?

I ordered a used laptop on ebay about four weeks ago.

Today I receive an email from the seller that seems to have sent me a wrong model.

After reviewing it, I found out that it really is a slightly more powerful device.

It may seem disbelieving for one or the other, but I really did not notice it, because the device has no optical aberrations - only the model number differs slightly.

For the attached invoice, the intended device was also billed.

What would you do?

May I keep the device?

I look forward to your answers.

May I keep the device?

No, of course not, what do you think?

The UK should send you the right device and a return slip for the wrong device, then send the wrong device back.

That's exactly how I would do it