Same thing happens with Dell, I don't think it's possible to get through an order and checkout without an intrusive chat opening up on you.
I don't mind if it's an icon+label off to the side in a fixed position, it's handy if you want it. But when it opens up and interferes with you using the site in question, you lost me as a customer. And I'll actually engage with the chat to let them know they lost me because of it.
You should use chat widgets to get discounts.
You can almost always get an extra 10-20% off from a lot of places via cs staff because that's what they're allowed to give and they're incentivised to give it to you because they want good survey feedback.
Dell and Lenovo are notoriously bad with this to the point I exclusively place orders through their chat staff.
P.S. I always buy the phone outright, was just getting it through the carrier, the price was competitive.
And yes, the inefficiency of it all makes my eye twitch uncontrollably also.