If I "expect a hotel to not give out ANY information", I would expect the property to not even acknowledge if I was or was not a guest.
While in the OP's case, additional information - check in & check out dates - was provided, it sounds like simply confirming the OP was in house would be sufficiently troublesome for the OP.
I think there is a level of reasonable expectations. It's very common that people call a hotel and ask for a guest by name so they can't just stop that practice because it would be simply impractical.
Agreed that the case of the OP seems murky when it comes to this situation. If you have someone who it stalking you for whatever reason, be it a personal acquaintance or an overly zealous local supplier that you can't shake off then IMHO there is no other way than to stop staying at this hotel for a considerable time. Jakarta has tons of hotels and sometimes we have to make a choice as to what's more important to us, points or comfort.