Change starter kid delivery address and location

I signed up as an Xfinity customer today and am having a very poor experience. Before sighing up, I explained to the the Xfinity agent that I would like the starter kit delivered to my current address, not the one I am starting service at when I move there. The agent advised to place the order then call to have the delivery date and delivery location changed.

I am now being told after calling in that delivery date and cannot be changed. How do I go about making this change?