Errors on Leroy Merlin becomes customer's problem

I ordered a cupboard online and without any feedback, they just cancelled my order, without communication on a refund etc or how they will improve the service and what they can do to better the inconvenience.

There was an error on pricing, hence the cancellation, but I already cancelled my other order from another company as I thought I was getting a much better price at Leroy Merlin. And this is an error on Leroy Merlin's side, how is this now my problem???

And then the customer service is pathetic with no real assistance or guide on the way forward.