Data usage with iTuens media services

Hi

I generally use between 500MB an 1GB of data per month. In the last few days the iTunes Media Service appears to have used approximately 3GB, 1GB of this was over a 24 period where I had not changed any settings and had been in WIFI range for the vast majority of the time.

Can anyone explain this or suggest how to resolve the issue? I have disabled Mobile Data for Music and the iTunes Store but won't know if this has worked until my monthly allowance is refreshed.

Any other suggestions or supported would be appreciated.

Thanks