using iphone 6s in mexico
My mother told me that she had Apple do something to her iphone at the Apple Store and she could use it in Mexico exactly like she does in the US, without paying anything extra. I cannot find anything about this searching online and wonder if she's confused. She has AT&T and I have Verizon, if that makes a difference. Any help is greatly appreciated. The plan with Verizon will cost us an additional $120 for our 11 week trip.
iPhone 6s, iOS 11.2