That sounds eerily like my experience 8 months ago with 'Verizon 5g Home Internet'. Lied to by the used-car salesman: "we'll give you $100 in credits", and when I canceled (mostly due to customer service saying "I see your $100 of credits, they are pending approval", then a few weeks later "credits? there are no credits showing on your account"), got nothing but runaround and a claim that my returned modem was damaged. I AM doing business with a Verizon MVNO (Visible, just because they provide the best deal for me, and don't really even HAVE customer service), but I will NEVER directly do business with Verizon again.
(Sorry; off-topic, but I needed to rant)