WASHINGTON (AP) — T-Mobile US knowingly made hundreds of millions of dollars off its customers in potentially bogus charges, federal regulators alleged Tuesday in the first lawsuit of its kind against a wireless provider.

The lawsuit by the Federal Trade Commission, which fueled a separate federal investigation, demands that T-Mobile refund the money to consumers for subscriptions to premium text services such as $10-per-month horoscopes that were never authorized by the account holder. The FTC alleges that T-Mobile collected as much as 40 percent of the charges, even after being alerted by other customers that the subscriptions were scams.