Calls offering customer service will have to use a specific number code. Congress has taken an important step to prevent these calls. spam with conventional landline or mobile phone numbers that prevent you from knowing who is on the other end of the call before you answer. The Social Rights Committee of the lower house approved the Customer Service Law this Wednesday, which incorporates this modification as its main new feature. The initiative will still have to go to the full House and then to the Senate before receiving final approval.