Your first case depicts a picture where a full refund of the whole stay should be offered, along with some compensation. The Hotel fell very short by offering a 50% discount, just verbally, without any actual reimbursement. A sad story, without any positive spins.
A basic hotel offers a/c, internet, hot water and a clean room within cleaning premises. The property you stayed at fell short in several points, thus a full reimbursement, along with a compensation as a Platinum member, is in order. Guests should have been transferred to a functional property, that simple.
In my experience at a Ibis, GM acknowledged a serious issue and within the same day points were posted in my account. This simple.