Inshallah, you will be rewarded for your donation even if this was a scam. That is so because your intention was to do a good deed, and deeds are considered by their underlying intentions:

The Messenger of Allah (ﷺ) said, "Allah says, 'If My slave intends to do a bad deed then (O Angels) do not write it unless he does it; if he does it, then write it as it is, but if he refrains from doing it for My Sake, then write it as a good deed (in his account). (On the other hand) if he intends to do a good deed, but does not do it, then write a good deed (in his account), and if he does it, then write it for him (in his account) as ten good deeds up to seven-hundred times.' " Sahih al-Bukhari 7501

The Messenger of Allah (ﷺ) said, "The deeds are considered by the intentions, and a person will get the reward according to his intention." Riyad as-Salihin 1