we didn't record our call and they claim the call never happened
It certainly seems like it is worth putting everything in writing yourself at the very least. I've had a few telephone conversations with financial people of various kinds where employee A says one thing and employee B says the exact opposite. If you can't get them to send you a letter stating what they say on the phone, you can write to them and basically say 'you said this on the phone, will you please confirm in writing'. And if you don't get a reply, take your business elsewhere.
It certainly seems like it is worth putting everything in writing yourself at the very least. I've had a few telephone conversations with financial people of various kinds where employee A says one thing and employee B says the exact opposite. If you can't get them to send you a letter stating what they say on the phone, you can write to them and basically say 'you said this on the phone, will you please confirm in writing'. And if you don't get a reply, take your business elsewhere.