Thats wasn't the case for me at all. they knew exactly what to do and I have never had an issue. Sounds like the people in that store don't know what they are doing.
I have to agree. I think they're trained (mostly for liability purposes) that if someone brings in a phone that they don't sell or have ever sold, they probably "can't touch it" which would likely be handled by the employee saying to the customer, "Sorry, we don't support that phone." Coming from retail sales many years ago, I can understand why they would tell people this. However, there are some employees that actually know about things that aren't taught to them by a store manager and these are the people to talk to. This would explain why the rest of us with Nexus 4's have no problem getting them activated by AT&T.