The solution there is the same solution as the US. If the US introduced a (for example) 4x median salary fine for every year an employer employed someone not legally eligible to work the problem would fix itself. If they did not keep records assume 5 years or whenever the person's visa expired, since that is the most common case of illegal immigration.
But the businesses WANT a class of people they can underpay who can't gain access easily to legal services when the employer screws them over.
If the people are employed legally and are being paid the minimum wage, then your complaint is with the government and you should elect people that will raise the minimum wage.