Report to Army Reserve unit?

I just completed BCT and AIT and returned home on 12/15. I was instructed to report to my unit within 72 hours. I called the SSA and was told to have a good weekend and that I would receive a call back on Monday this has not happened. I called and left a voice mail for the SSA late on Monday. I have yet to physically report to this unit and it’s about 100 miles from my home. What should I do? I also have leave that needs to be paid out before it is lost. I have so many unanswered questions and could us any help you can provide.