I have similar thoughts about Texaco and will not use their products, when the lease expired on the workshop I was renting which was part of a Texaco Service Station the 1980s I spent months and legal fees trying to negotiate a lease with Texaco direct, but my solicitors had to deal with Texaco at their Knightsbridge London Property Services Division. They were demanding a rent three times market value, with a full repairing lease, and an in going fee although I was already there and the final nail in the coffin, the option to evict me within three months, even though by then I had rented the place for nearly four years.
All this at the start of a recession, whilst all that was going on I had to let go options to buy/rent other premises, so when I found it was empty earning them nothing for over three years later I felt they deserved it!
Finally I fully agree about the " They say the best advertising is word of mouth" as all my business came from that and proved to be a loyal customer base over many years.