Cheaper Internet Access

In the interests of saving a bit of money, I've changed my internet access package (still with the same provider) to an account that is limited to 2GB per month. I don't know whether this was a good move or not, the main reason was uncertainty about what package I was on anyway. I signed up to a 512KB package for 19.99/m but since signing up for that they have introduced higher bandwidth packages for the same amount - it seems from the online account details that I was still on the 512KB bandwidth for the same cost as 1MB. So any, my thoughts now turn to what 2GB per month actually equates to in real usage terms. You see, my fear is that I might exceed this some months. I use the Internet at home for work and we use it evenings and weekends quite a lot. I'm sure it must all mount up. Also, I have been a bit dumb and not looked up what happens when you exceed the 2GB - am I charged per MB or is access just cut off? I should have found out first. The other thing, was that in the promotional email it said that the 1MB bandwidth would be doubled to 2MB however, there was no mention of that when I actually went through with the upgrade. ISPs haven't really improved a lot in terms of giving out detailed information - I hate that side of it.