They will send it back to the address listed on the DHL slip/envelope that you sent, SQ. You are Ocho Rios, I think, so there should be no issues with delivery to you. Some persons must go to the DHL depot to collect packages because DHL does not deliver to their district or location. They deliver in the major towns and some surrounding areas, but otherwise you have to go to their office to collect it.
Edited to add: Regarding your turnaround time, SQ, it may not take a long time just because you have a good amount of time left on your medical. Remember the medical date is the absolute extent of the validity of the PR visa, but I have seen where someone's wife was given less time than the expiration of her medical to land. Her passport would have expired close to the time her medical would, so her visa was set to expire 4 months before her medical actually ran out! Also, take in consideration that KG has quotas to fulfill, and it may be that they shorten the validity of visas to ensure that persons land before the time for their quota fulfillment runs out.