S.H.E was alleged to have 43.4 million of downloads (through China's No. 1 mobile service carrier), according to the reference "http://ent.qq.com/a/20110624/000602_1.htm". However as per the same reference, it has been clearly stated that the 43.4 million of downloads include both the entire track and ringback tones, while the latter should not be counted as sales since it would be unfair to other groups.
And according to another source "http://www.baike.com/wiki/%E5%92%AA%E5%92%95%E6%B1%87", the artist who was alleged to have most downloads of entire track through the same carrier was WANG Leehom, with 0.56 million of downloads, therefore S.H.E's digital sales were no way more than that.