1) early check-in is not guaranteed, BUT, as a Plat, I have never been denied it. It sounds as if they had blocked a room for you, so am guessing they did not have another of the same room type available. (ie - if you booked a 1 BR, they only had studio's ready). I would have asked why they could not give me another room- and then made a decision based on their response.

2) most RI's are clueless as to the Plat amenity. you can try to collect - but am guessing you will get the "we gave you points speech". if they do, and you didn't, certainly argue it out.

3) based on your arrival experience, do you really want to spend 15 days here? I would not. ( as well as the fact I am not about to give up 50% of my points for a 15 day stay)

Finally - (perhaps you know this, but if not....). that is a terrible area to stay for more than 1 day. There are no good restaurants or shopping, and if you have your family with you, there are very limited park/playground or other family activities close by.

Between your check-in experience and the area, I would consider changing locations. If you are unfamiliar with ATL, PM me and I can make some recommendations that are not too far away but will provide a better experience...there are LOTS of Res Inns not too far away that are much better!