firdtly, the employer should have a meeting with all of you, the employees and explain what is happening and why they will be retrenching  this is especially directed at the employees who will be retrenched.
on termination of employment you are entilted to any over time worked, as well as ny leave days owed to you and depedning on the length of your employment, you are entilted to severance, one week for every year in service / worked for the company.
the LRA aclso distinguishes between small scale and large scale retrenchments. so if you belong to a uion, make sure to communicate to tehm and if you are unsure about anything else, you may call the department of labour and you may follow this link http://www.labourprotect.co.za/retrenchments.htm