The important thing to note here is the pricing model in Windows Azure - I'm talking about hosting services which is the deploying of services and running services in the cloud bit of Windows Azure - not the Service Bus or SQL Azure - they have different pricing models.
The charges are based on "compute hours". Although do note there are two types of pricing models within Azure. The first is a pay as you go type model so you only pay for what you use. The other model is a fixed contract where you agree to a fixed discounted monthly fee for a given time frame and any excess usage is charged at the standard rate.
Do be aware, no matter whether your services are being used or not even if your services are not running this still eats into your "compute hours". It sounds unfair from the outset, but I don't think it is unfair as for those charges you get a dedicated VM, CPU, memory etc to your services. So you can be sure you'll have the resources available to serve up requests when needed.
So as I am an MSDN Premium subscriber, I opted for the promotional offer of "free" services. So under this offer you get 750 "compute hours" under Windows Azure, 1,000,000 ACS transaction requests on AppFabric, 3 web edition databases etc. See here for more info on this promotional offer: http://www.microsoft.com/windowsazure/offers/popup.aspx?lang=en&locale=en-US&offer=MS-AZR-0005P
Utilization over the "free" 750 hours will be charged at the standard rate.
Of course that works out to be one service constantly deployed in the cloud for 24 hrs a day for 31 days. So essentially free.
Now regarding my bill I received, the good news is Microsoft refunded me the £187.10 due to the fact I forgot to remove the services and the fact that I didn't realize they were still deployed as I have only been using the Service Bus within Windows Azure lately (now known as the AppFabric). So I am grateful to Microsoft for doing this as they legally didn't have to.
So when I noticed the bill, the first thing I wanted to do was delete the services to prevent further costs mounting up.
So I went to the Windows Azure maintenance portal over at http://windows.azure.com/ clicked on Windows Azure and noticed the services. But the Delete button was disabled:
This is not particularly intuitive, but you have to click "Suspend" which is the same as stop. Then the Delete button becomes enabled that allows you to delete the services!