To be honest , I am not law expert, I dont have very experience about citizenship laws in Iran, but as far as I know (You should consult an expert if you want to become sure) Iran's law written in a way you cannot get rid of your citizenship, even if you change your nationality, I think Iran government would consider you an Iranian. This law is ridiculous (I know). But I think the reason they wrote law in such way was not dictatorship or something like this , there was rationality (at least in their mind) behind such law.

p.s. I want to make you sure, the information I wrote in this comment maybe are wrong, so do not rely on them.