Worse than that: imagine that they not only charge more based on the brand of electric car being charged, but they also sell (or are planning to sell) their own

Worse than that: imagine that they not only charge more based on the brand of electric car being charged, but they also sell (or are planning to sell) their own brand of electric car, and they know it won't be as good, but they'll offer to let you charge it for less than the other brands.