Company - it or they?

Confusion over this is something I come across frequently. Usually, a company (e.g. Perfectly Write) is singular (see how I used is there and not are?). So 'Perfectly Write is a company providing proofreading services and is based in Kent' is correct; 'Perfectly Write' are a company that also offer copy-editing services and are pretty good at copywriting too' is wrong (well, the grammar is, hopefully the sense is not!).

Often, I look at material in which the company switches from singular to plural pretty frequently and the whole document smacks of inconsistency. Like this: Perfectly Write offer a range of services to publishers. They provide proofreading and copy-editing, and the company has experience in publishing. Perfectly Write are dedicated to ensuring consistency in text - its ethos is to make things 'perfectly write'. I would correct this to: Perfectly Write offers a range of services to publishers. It provides proofreading and copy-editing, and the company has experience in publishing. Perfectly Write is dedicated to ensuring consistency in text - its ethos is to make things 'perfectly write'.