In the event that it is a user who expresses his discontent, you must apologize and give him the pertinent explanations. Once this is done, you will be invited to follow the conversation privately, either by email, customer service number or by private message. Never give rise to an unpleasant situation in public. If that situation were to happen, many users could change their opinion of us, for the worse.
If it is a troll, it depends on the seriousness of the Phone number database accusations and the frequency, we must show interest in their discomfort and try to convince them or offer them some kind of compensation to put an end to that situation. You should never get down on him. Treating them with respect and trying to understand their discontent, they end up retracting it themselves. If the accusations persist and turn to insults and disrespect, they can be blocked.
On Twitter, complaints come in the form of mentions, in these cases there is no need to start a discussion on our timeline. It is convenient to look at the profile of the person who is complaining and differentiate if he is a dissatisfied user or someone who is looking for notoriety. If you are a dissatisfied user, it is best to send them a private message asking for the data and referring it to the corresponding department. If it is someone who is looking for notoriety, it is best not to give it to them because we only intensify that situation more.