Thank you for your post.
I answered your identical post at:
However, for others reading this thread, the Dial Phone script step will work properly when referencing a field. However, if you type in a number directly, it will dial a random number.
Another option would be to use the "Open URL" script step using the "tel:" option.. For example, "tel:5551212" or "tel:" & Fieldname
Are you referencing a field or a string? Does the script continue after the Dial Phone script step? If you post your script, it may be easier to understand why this is not working as expected.