Well I'm not sure about this, but I think the sense may be that the insurer normally has the right to terminate an insurance contract if there is no longer any possibility of an accident covered by that contract occurring (e.g., if it's motor insurance but the insured party no longer has a car). In that case he may gets his premium back. This clause states the terms that apply if he cancels it for *any other reason.* So for the whole sentence you could add this emphasis to make the meaning clear: "The insured party has the right to cancel the contract *even if* the possibility of the occurrence of an insured accident still exists, but in that case [pri etom] any premium paid to the Insurer shall not be liable to repayment."