you can approach the department of labour and file a report against your company. The department of labour will then have to investigate further, if your allegation proves to be true than a recommendation by the department will be drafted and submitted to your employer. The employer will then have to comply with the recommendation and you should be issued your IRP5 form.
Option 2,
You could approach the shop steward or your union representative and tell them about your problem, if the matter is serious a meeting could be held with the company in order to address this issue.
Option 3,
If the employer fails to adhear to the department of labours recommendation you as the employee could approach the court and file an application to compel.