Is there a business you absolutely refuse to do business with?

I no longer buy Nabisco products.  They accepted millions of dollars to continue their business in the U.S.  they took the money, upgraded their processing plants and then sold at least part of the company to a Mexican entity and moved those jobs to Mexico.

I haven't bought a Yingling beer for decades.  I once sent them a sample of one of their beers I thought might have been tampered with - I was doing them a favor to alert them to a possible serious problem - and they refused to repay me for the postage, even after several phone calls.  They ended up losing my business, much more than the postage cost.

I don't do business with Walmart in any significant way.    Disney is another one I try to avoid.

Verizon. 

Every single company on this web page:

https://en.wikipedia.org/wiki/Category:Tobacco_companies_of_the_United_States

Some American friends are boycotting Starbucks. I never had an desire to go there anyhow, so I join their boycott. 

No -- wait - - I take that back . . . 

There's several I won't have anything to do with.
Here's just a few of them.

Starbucks
Dicks Sporting Goods
Cheaper Than Dirt
Subway
Walmart
Guitar Center