Reliance Digital — I ordered item and they cancelled without my prior information.

I ordered a laptop( order noRDF[protected] from reliance digital while refusing other websites deals. They gave me a date of delivery and when the date came first they changed the date of delivery and second day they sent me a following message -

Dear Rakesh, As requested by you, your Order RDF05718455 has been cancelled. Please check your email for further details. Reliance Digital.

This shows completely unprofessionalism and they snatched other websites offer available during that time, from me.