This is from a "force majeure" clause according to which the contracting parties are temporarily excused from performing their contractual obligations if they are prevented from doing so by some unforeseen disaster, strike, etc. 5. Não obstante o previsto nos números precedentes, ocorrendo facto de Força Maior, a Parte em relação a qual a prestação da outra tenha sido realizada, fica na obrigação de repeti-la a favor daquela que a prestou. 5. Notwithstanding the foregoing provisions, if a Force Majeure event occurs, the Party for which the other Party tendered performance shall remain under the obligation to ***repeti-la*** a favor daquela que a prestou" Just guessing from context, the last part might mean something like "the party that received the service is still obligated to pay the party the performed the service". One problem with that interpretation, in any case, is that the customer can't receive a service if a disaster makes it impossible for the contractor to perform that service.