4. No surety may terminate the suretyship before the last day of April following the date of issue of the guarantee policy, and the collecting agent must cease to act as such as soon as the suretyship ceases.
However, upon proof established to the satisfaction of the prothonotary of the Superior Court, who received the said security, that the collecting agent is no longer acting as such and has satisfied all his obligations to his mandators, the said prothonotary may shorten the period thereof determined by this section.