The exact issue of your question is rather unclear. The retrenchment procedure could take some time, in larger companies it could take up to six (6) weeks to implement and conclude. During this time you are still required to fulfill your duties as an employee of the company. The company may retrench a number of employees for various reasons, the notice given to employees is the first step in the process.
The employer may choose to waive the notice period as stipulated within your contract. This depends on the agreed upon settlement between you and your employer. If the process has not concluded and you have not been issued with a formal letter of retrenchment you are still an employee of the company and must follow instructions from your superiors. If you do not comply you as an employee could be open to disciplinary procedures by your employer.