Extend all consumer rights law to private sellers purporting to be businesses

I recently believed I was buying from a reputable, bona fide business. When I asked to rescind the contract because the purchase was not fit for purpose, I was told the purchase was a private sale and I did not have consumer rights. In court the judge could not award my claim as although the seller had purported to be a business and there was evidence of this, he wasn’t, meaning I had no consumer rights. I believe if someone purports to be a business, they should be accountable as one.