ECE Evaluation of International Transcripts

Hi... I just had my international transcript evaluated from ECE and how come their evaluation I think is too low.. I got my C's converted to Ds! But this was not the case in all of it. So I don't know it's really like that..I mean, if C's are D's, how come some of the subjects where I got C's not converted to D's? I'm just confused.. so in effect, my overall GPA was so low! Did anyone run into this problem? Thanks! :angryfire