Hi petkow,
Unstructured Supplementary Service Data
Nokia et all tell us we are not using phones but computers, being informed when I spend €00.01 or even when I have just used the Data Service and my balance has not been affected because I've already spent the dialy max which blocks the phone untill message is cancelled seems like a "super DUMB phone" to me.
I have GPS on the phone (N82) which uses small amounts of data and which I switch in and out occasioally and have to cancell these "DUMB" mesages seems just plain "DUMB" to me.
It should really be a choice from Yoigo whether I want to get them or not, and if need to check my balance then I can do it when I need to.