The best solution that I came up with was to contact the tenant to see if we can resolve it simply first.
If that does not work you should contact a real estate attorney that is familiar with local laws to determine what the next action should be.
It is likely an oversight by them. In your conversation with them it is important to be polite and professional.
It is important as a landlord to be educated in these laws. Before conducting an action, it is a good idea to check with an attorney first.
Even if your lease says something about turning off services, it is a good idea to check with an attorney in your location before taking such action.