求助 renter problem

租给了一家黑人， credit score 650,  说水费贵， 很少浇水 (has automatic watering system)， 也没有割草， 怎末办？

The lawn is yellow right now. They agreed to take care of the gardening when they rented the house.  They also agreed that they would water the lawn and mow the lawn two weeks ago when the neighbour complained.  But they did nothing.

Please help!