Question about a number, red flags, etc


#1

I have a question for the more savvy folks here, my friend needed help getting back into her AT&T account and looked up a number off the internet 1-888-828-5947 for support. They way she described it, they wanted to charge her 300 dollars to get back into her account and they said someone in Germany hacked her account. They also gave her a different number to call back (1-866-978-5701, Mark Wilson), when she found the information they were requesting from her (answers to secret questions,etc). I researched the number and it was tracked to several different support services. Can anyone give me some insight or opinions into this? Thanks.