I work in a call center and get calls from all kinds of people. Some people are nice, some people are conniving, some people are nice and conniving, some people are mean, some people are mean and conniving, some people are just so clueless they can't help but sound nice, and some people are just so clueless and mean that they come across as the least enjoyable callers of all. The callers of the latter most category offer no intellectual challenge and no personal connection, whatsoever.
Maybe your mom falls into one of those categories.
(The key to solving a person's tech support problem over the phone is to solve the problem with the information at hand. It sometimes takes even a mean and clueless fellow or gal on the end to gather that information for you to assess. If the caller is uncooperative to that extent, the call cannot move forward and the caller's problem cannot be solved. In some instances, the caller will say, "You know, I'd just like to cancel." Here the one good tactic is to interject that the problem is "so simple to solve, anybody could do it." I don't know what usually goes through the mind of the unruly caller, but in many cases that tactic does the trick. They start to calm down and follow your instructions.)