I would like a US based call center

One of the best things about TMobile was their customer service.  But the last 2 times I have called in, I have gotten someone in a different country.  They have been nice and boy they try hard. But in each case they have REALLY struggled to find the issue, understand what I’m asking, and navigate the systems.  With a lot of patience on my part, I have generally had my questions answered.  But in every case, these were questions that could have been solved in a fraction of the time.  Where have all the U.S. call centers gone?  I know it is MUCH cheaper going overseas, but it is killing my customer experience.