Sorry to hear about your problem. I'm sure they will eventually get to those emails but I recommend you keep on sending them emails until you get a response. Spamming the same message across every forum category is not likely to get a response from them any faster, because they are hardly ever used by anyone. It sounds like some kind of automated error like if the site software sees you hit submit twice or something. I'm sure they will get it straightened out but if it goes too long you might want to consider a Visa charge back on one or both of the charges.
In any case I hope it all works out quickly and you are free to concentrate on the content here.
George - fellow student