Photo messages!!!

[amazingtoxic]

I sent a photo message the other day, after five mins, something came up on my phone, I assumed it was still sending and I pressed a button on my phone and it said sending cancled. So I sent it again (just once) The person I sent this message to has now recieved it five times. Whats going on? How do I stop it from sending more and will I be charged for these messages?

Thanks