Follow-up information: The Verizon support person connected me with a representative from Asurion. Their rep was able to tell me that two different individuals, from two different states, had used my credit card to pay the deductible for their phone claims. Neither of these individuals was on my account. She stated that my credit card had been compromised, and that I needed to call the credit card company and dispute the charges and get new cards. While this sound believable on the face of it, I find it difficult to believe, because the only activity on the card in the last four months was these two fraudulent charges, the last of which was made on May 21. The card hasn't been used for anything since. I would assume that if the card had truly been compromised, it would have been maxed out by now. Regardless, I will call the credit card company and get it addressed.