MOL was economical with the truth
1) If you had a flight within the first seven days of the restrictions beginning, Ryanair charged £35 for the ‘free’ transfer plus any difference in the fare.
2) The contract between the passenger and Ryanair (or any other airline) is frustrated because nobody can be forced by contract to undertake something that is illegal. The passenger is entitled to a full refund if they can’t fly. Just because MOL says they don’t have to give refunds doesn’t mean they can’t be forced to give refunds.