1. Draw up a clause in the renters agreement. Just in case someone like this is thinking of renting from you, you can attempt to preemptively nip this behavior in the bud by something as simple as a paragraph or two in the original agreement. Have a section dedicated to complaints and what kind of maintenance they should or should not contact you about. Obviously, the renter should communicate with their landlord if there is a severe problem such as plumbing, electricity, or bugs, however it is up to you what else you should be responsible for. If their toilet becomes clogged due to use or too much toilet paper, is this your problem or theirs? If a light is out because of a blown bulb which they can reach, should they have to replace it or should you? Simple things like this often slip our minds but are all things that others may come to you with a complaint about, even if it is outside your power to control.
2. Be accessible. In the event of something occurring which is covered in the contract as your responsibility, or even if it isn't in the contract, you need to be easily accessible to your client. Nothing upsets or worries a renter more than something going wrong and not being able to get into contact with the person who they rent from. We at Talley Properties are on call 24/7 just in case something happens, so we understand what it means to be there when needed. If the person is a chronic complainer, you always have the option of screening your calls, however that is cautioned against because many will catch on to that rather quickly. Remember to check your emails, your phone, and perhaps give a method of contact in case of extreme emergencies only.
At the end of the day, people will complain. One of the best things you can do is listen to them and attempt to fix the problem quickly. Always check up with your client at a slightly later date to make sure everything is going smoothly, and sometimes even check in when nothing has gone wrong recently to show you do care. If none of this works, often offering an early severance option will get renters to stand down as they suddenly realize that dealing with what they perceive to be inconveniences are rather small in comparison with having to move.