How? Look the reality of business is that the customer is always right. You're not a spokesperson for Vapi and neither am I. Even if both the company and everyone around clearly knows that yeah maybe those complaining should have just paid attention to the notifications, that's still an area for Vapi to improve its customer service, because a lot of people are complaining. The first tenet of customer service is to stuff the customer's mouth with a silver spoon if they want them to. And always listen. So how Vapi goes onto communicate such changes in a better way is up to them.
I love their product just as much as the next person and so this is just some constructive feedback for them to work on. A good product is nothing without good customer service.