A chart being scaled by pulling a sizing handle downward. With the shapes a little larger, there's more room to enlarge the font.
If you want the shapes in the chart to be bigger or smaller, scale the chart.
To scale: Point to one of the white sizing handles on the canvas border, look for the two-headed arrow pointer , and drag the border inward or outward. The pointer is a crosshairs as you drag.
To resize the chart on one side or from one corner only, simply drag the sizing handle. To resize the chart on opposite sides or from all corners, press CTRL as you drag.
If you clicked Fit Text at an earlier point to enlarge the font size in the chart, and then you scaled the chart larger, clicking Fit Text again should make the font a bit bigger, still.
To move the chart Simply drag it at the border using the four-headed arrow pointer . You must click the chart to select it first.