I did not say anything in this matter. मैं समझता हूँ यह भी ठीक है
I nothing said about the matter...
Ybi to shi hoga na
I have not said anything in the matter
That sentence will belong to Preterite tense, i.e. things completed in past tense.
I said nothing about the matter = मैंने इस मामले में कुछ नहीं कहा।
I have not said anything in the matter = मैंने इस मामले में कुछ नहीं कहा है।