When expressing agreement or acknowledgement of a statement made by someone else, there are several synonyms for the phrase "of course you said." One alternative goes along the lines of "indeed, as you mentioned before." Another option could be "absolutely, I remember you saying that." Similarly, you could also use "certainly, you've already pointed that out." Additionally, "without a doubt, you already mentioned this fact" would be a suitable substitute. In sum, there are numerous ways to rephrase "of course you said" while still conveying the same meaning.