the policy may be terminated at the request of the Insured at any time, in which case the insurers shall retain the customary short-period rate for the time this policy has been in force. This Policy may equally be terminated at hte option of the Insurers by seven days notice to that effect being given to the Insured, in which case the Insurers shall be liable to repay on demand a rateable proportion of the premium for the unexpired term from the date of cancellation less any reasonable inspection charges the Insurers may have incurred.