Is there a clear and obvious reason for it being half priced?
For example because it's a refurbished used laptop, in which case the price may well not be a bargain at all and it may well be over-priced for what it is.
Or it's an old, out of date model, in which case it might also be a bit overpriced for what it is.
Or maybe the original price that they are claiming the laptop sold at is being over exaggerated by them. For example they've sold you a laptop with an i3 CPU, and a mechanical hard drive that is half price compared to the i7 CPU with the 512 GB SSD option on that laptop.
Are you prepared to state the exact make and model and options (screen, hard drive, CPU, RAM, any graphics card) and condition of the laptop you've bought and the price you've paid for it?
If the worst happens and they cancel it, you should get all your money back.
Then you'll have a nice little challenge of finding a laptop that's even more suited to your needs for less price than what you paid for the cancelled laptop. There's a good chance that you can do this with the right knowledge and advice.