I had the same issue, called in E-ZPass, the rep said that he removed the vehicle from my account, but can't refund me because if the vehicle is on my account then it must be that "I added it to my account!!", & It can't be a system error, so I asked to speak with a supervisor, then the rep changed his desicion & said that he'll put in a request for me to get refunded. A week or so later I got a letter that E-ZPass refunded me $120!!
Looks like a had a had a better experience then most people.