Actually, Amazon has ‘every right’. It was what you agreed to when relinquishing your customer service responsibilities to Amazon when choosing to utilize Amazon’s FBA services.
Over the years, we too have had this happen. Most of the time, within 45 days (as per FBA reimbursement policy – which you can read from the ‘help pages’ if you wish), that concession is credited back; paid for, as you put it with “Jeff Bezo’s money”.
As per the FBA reimbursement policy, if this concession is not credited to you automatically within 45 days, you open a case and Amazon will manually process the reimbursement.
The only true way to avoid these concessions and having to wait to be reimbursed is to fulfill your orders and provide your own customer service on them.