The ornamental design for a mixing and dispensingdevice, as shown and described.
FIG. 1 is a back and side perspective view of a mixing and dispensing device embodying our new design;
FIG. 2 is a front and side perspective view thereof;
FIG. 3 is a top view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a bottom view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a front view; and,
FIG. 8 is a back view thereof.
In the drawings, the stippling indicates a contrast in appearance. The broken lines depict environmental subject matter only and form no part of the claimed design.