I wouldn't deal with Thomas Cook (now defunct) after their treatment of a family when two children died of carbon monoxide poisoning in one of their properties.
Evri who have lost two of my orders from Cos and for being generally crap.
A well known foot care company with several shops in the South East who have a rubbish online booking system; even the receptionist told me I should have phoned up rather than book online.
P&O - after fire and re hire
The company (a professional partnership) who took 40% from employees pay during part of the pandemic because they were worried about cashflow (whilst transferring a stash into one of their wives' accounts). The senior people in the business were still drawing huge salaries whilst employees were going on UC. They went on to have a very profitable year in 2020.
I heard someone say that people would remember the way that business owners behaved during the pandemic.
NatWest - unknown to me my deceased ex husband had transferred hundreds of thousands into a legacy joint savings account (opened over 40 years ago) that I had completely forgotten about so hadn't removed my name from.
Their fraud investigation person was awful, when I said I knew nothing about it, told me I 'sounded' like an honest person. It was months of stress.
My ex had done nothing wrong either, it was a complex family matter and nothing to do with me.
Generally I find that when a business gets PE investment quality and customer service suffers.
Tesla or anything to do with Elon Musk. Don't need to explain.