Your connection speed has nothing to do with your download speeds, it's only a theoretical maximum. There are many other factors involved such as server load, ISP load, good old Aussie copper wire causing bottlenecks, the route your data takes to and from the server, which I understand is in the USA and other factors such as the file hosts connection speed etc. Unless you have a direct fibre connection to a server next door that nobody else is using at the same time, you are unlikely to get 12 megabytes per second downloads.
Merry Christmas
Graeme.