Seeing an increase like this would be a concern of mine as well. Especially if you don't get close to that allowance on a month to month basis. While I can't say why for sure right now, I am happy to look into this for you. I have sent you a Private Message here so that I can gain access to the account and gather more details from you.
ErinW_VZW
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If my response answered your question please click the _Correct Answer_ button under my response. This ensures others can benefit from our conversation. Thanks in advance for your help with this!!