When typing on an iPhone, it doesn't tell you how many characters you have left. So texts can come up as multiple ones when received. Question is are you charged for 2 texts if you send a 200 character message. Or just 1?
I have character count on mine. Since you appear to not be US based (since we have unlimited SMS plans), I don't know if your country has CDMA, but CDMA carriers will split the texts up, since they can't send as one chunk. iMessage goes as one chunk since it's data.