Okay,I see where I went wrong now,thanks.I have used BMCargo for years for receiving packages and letters. I just checked their website, and on the registration form there is clearly an option "localidad", where you have to choose to which of their locations you want things delivered to. So indeed you should have had this selected. (https://bmcargo-online.iplus.com.do/zz/Membresia.aspx?pid=214)
For your other question I cannot really give a good answer, as while they have a good tracking system, it has always been me who has kept track where is the package, and went to the office immediately when it has arrived based on the website. So by tracking the package you for sure get to know when it has arrvived, but I'm sure there is some kind of notification system in place as well. At least with me they have always been really helpful, so you might want to confirm with them.