"říkali" is normally the masculine plural form, but it's used for the feminine plural here. Ok but what's the point? Aren't both "říkali" and "říkaly" pronounced the same anyway? as are all past plural forms of all the verbs?
There is no point worrying about this. It is spoken vernacular, you can write it with i or y, it doesn't matter. Personally, I would have written it with y. The main point is that even the neuter ending is the same and not říkala.