That's barely a slap on the wrist for Big Magenta. More of a gentle tickle, really.
Using free data sources like Yahoo Finance, you can easily see that TMUS collected $33.9 billion in revenue over the last four quarters. $1.1 billion trickled down to become bottom-line profit. This $48 million fine is a rounding error compared to the company's sales and just 4.4% of its trailing profits.
Put another way, the company has 67 million total subscribers. If T-Mobile paid back the entire fine directly to its customers, it'd be a grand total of 72 cents each. Please sir, may I have another?