from the experiences of making about a doz calls incl those disconnected while on hold and those did not get any results, it does NOT really matter which number you call - the call just get routed to the First Available Slot in the phone network. Whether you get a competent rep is a PURE LUCK. Usually you can tell from the first few min of conversation whether the rep is willing to help. If that doesn't sound so, just yuca because you would most likely not go anywhere with such a rep. The unfortunate part is, even the rep is willing, s/he may not be competent , and the help desk rep s/he gets may not be willing, so the outcome is the same as an unwilling rep.
however there are some very good reps who can help but it is almost purely by chance you get one on the first few tries.
of all the years I used miles and points this has been the worst case of mess up and the worst case needed huca to eventually sorted things out.
it is much much worse than the CO/UA merger and dealing with Indian call centers.