A few years ago I was in a T-mobile store (making the switch from AT&T) and the sales guy kept trying to get me to include add-ons to my base contract (e.g. unlimited international calls).
He kept trying to convince me, and I kept saying “no I don’t want that”. At the (final?) step when reviewing the contract I saw he’d still included some of the add ons.
I asked him to remove them, and he started the spiel about why I should include them again.
This is the rudest I’ve ever been to a salesperson, but I didn’t even say goodbye: I just walked out, went home and ordered a sim online.
I’ve often wondered if he was just new/poorly trained or actually intentionally trying to trick me.