a registered letter to their registered business address.
Bravo Sir/Madam! A troll for the ages.
I am constantly appalled by companies that don't have a phone number, address, or email on their website. Only some pathetic Web form, and sometimes not even that.
The hard truth these days is that Twitter is very often the most effective way to contact a human being at a large company. Apparently public shaming motivates them.
As for the value or veracity of Twitter, that depends entirely on how you use it. Some very smart and very knowledgeable people use Twitter intensively, and if you choose who to follow you can get incredible insights.
Of course there's also @realdonaldtrump.