The transformer in the residential area is broken. After the power company is replaced, the property company informs each user to share the cost. Is it reasonable?

Unreasonable, for example, if the power transmission transformer in the power plant is broken, can the power users at the lower side of the transmission be compensated? The power supply bureau sells electricity to users, and we pay the electricity bill. As for the transformer you mentioned, it should be their infrastructure (in layman's terms, it is equivalent to snack car selling snacks in the street), so you should argue with them.