Admitting it had overbilled customers who accidently launched web browsing sessions on their cell phones, Verizon Wireless said on Monday that it would issue refunds of between $2 and $6 to more than 15 million affected customers. The company’s action, however, is not enough to stop an ongoing FCC investigation into the matter that was initiated last January in response to hundreds of subscriber complaints. Monday’s disclosure represents a significant turn in stance for Verizon, which told the FCC late last year that it did not charge wireless customers who launched and then immediately ended web browsing sessions. Dated as far back as 2007, many of the complaints received by the FCC allege that subscribers were erroneously subjected to data charges of $1.99 when their mobile phones were not in use, when the handset’s web browser button was inadvertently activated, or when subscribers accessed trial applications that were supposed to be offered for free. Confirming that her company will issue up to $90 million in total bill credits or refunds to affected customers over the next month, Verizon Wireless deputy general counsel Mary Coyne acknowledged that, “over the past several years, approximately 15 million customers who did not have data plans were billed for data sessions on their phones that they did not initiate.” Coyne further stated that company officials have addressed the problem “to avoid unintended data charges in the future.” While applauding Verizon’s announcement, FCC Enforcement Bureau Chief Michele Ellison promised that the bureau “will continue to explore these issues, including the possibility of . . . penalties,” as “questions remain as to why it took Verizon two years to reimburse its customers and why greater disclosure and other corrective actions did not come much, much sooner.”