I have ATT and getting extra charges?

I have an iPhone with AT&T, I have unlimited texting and mobile to mobile calling, a 3072 MB data plan. I have not gone over on data, not even close, and I'm being charged extra for "Text/I'm
Messaging MKT SMS DOMESTIC $0MSG I'm/ INT $0.25MO - MKT2 Int'l Text Messaging Billed" Under s section in the bill that says pay-per-use usage. Someone tells me it's roaming charges but I've been in New York and I never left. So what are these extra charges for? The ATT phone lines are down right now and I can't even call them

Its obviously a text message thing. You will have to talk to att to figure it out. It could be an error.Id it is complain like crazy cuz you should get a discount.