Hi there Janita,
I did an intensive course for 6 weeks at AIL last fall. I really enjoyed my time there - the staff is friendly and the teachers are very good. You can consult the prices or enroll directly from their web page
My Spanish got a lot better during the 6 weeks as I advanced from level A2 to level B1. It was a great experience, as the atmosphere is very open and friendly, I made a bunch of new friends that I still keep in touch with. Also the activities help you to get to know Madrid which was nice.
I would strongly recommend AIL for you.