Wrongly paid amounts of annual bonus

Today on 6th November 2024 we received our annual bonus on our pension. The amount we should have gotten, should have been 8.33% of our annual salary. Unfortunately it was not true. I received R3000 less than what should have been. Mmy relative and a few friends contacted me to ask what is wrong. All of them has tried to call Sentinel to no avail. Is their a way this can be resolved. H. E. Harris