What actions are prohibited for a provider according to Article 19 of the law?
According to Article 19 of the law, the provider is prohibited from concealing the commodity, refraining from selling it, not providing the service to the consumer, controlling the price, monopolizing the commodity, obliging the consumer to purchase certain quantities of the commodity, adding certain terms for using the service or selling a commodity or another service with it, or charging a price higher than the declared price.