No, he’s wrong. Motability will pay the subsciption for the length of your lease and BP will give you a £25 credit when you sign up, you also get 50% discount off a hot drink at a Wild Bean cafe’s. Full details are on the motability website,
https://www.motability.co.uk/whats-available/electric-cars/charging/public-charging/
If you can get the free home charger it’s certainly a much better option, public charging is anything but cheap.
Please excuse spelling/typos. Apart from being a clot it turns out I had one on my cerebellum that's now causing various problems!