Safety could be anything, that a pilot is drunk, the aircraft has a technical issue, that the aircraft is a grounded MAX etc. ... Don't be shy to name and shame the airline, try putting in a claim with your card provider to the effect that you didn't receive what you paid for and under EU law whatever etc. , if possible I always prefer to pay thru PayPal and a pain in the butt they may be if the airline doesn't respond with a satisfactory answer then one normally wins.