One lucky guy and one extremely unlucky guy IMHO.While we all run the risk of "anything could happen at check in" on these special rates I think it is important to stress that what unfortunately happened to you is very much the exception .
I hope you get some accountability from the OTA involved and are rightfully reimbursed .
Perhaps the delay in "doing the right thing" has been caused by some behind the scenes bickering between the hotel and the OTA about who was to blame ?
Whatever I hope things are eventually resolved to your satisfaction.