Same applies in person. I’ve had people knocking on my door offering a discount on my electric bill.

— You just need to do accept <whatever, I forget> and you’ll pay less.

— But I don’t want to switch providers, I’m happy with the current one.

— Oh no, you’ll stay with the same provider, we’re with them, that doesn’t change.

— Alright, then I’ll call the company to discuss this further and get the discount.

— Unfortunately, this is only valid this way. Not by calling or online.

— Then I’m not interested. Bye.

One of my neighbours was tricked at a different time by a similar scam, forcing them into a contract with a different company.