It is prohibited to harm the neighbors, and it is highly recommended to be kind with the neighbors and to deal with them in a good way.

Based on compulsory precaution, one should not desert a believer for more than three days, even if the latter was wrongful to him. It is sufficient to satisfy this obligation by greeting him (e.g. saying 'salam alaykum'). If the other party insisted on the abandonment, he will become the deserter.
This prohibition has three exceptions:
First: if the desertion was to forbid the wrong.
Second: if the desertion would lead to a benefit that the Sharia recommends, like - for example - if desertion leads to paying attention towards a truth that could remain hidden without such desertion, or similar cases.
Third: if the reestablishing the relationship would lead to demeaning oneself. One should be careful in not confusing arrogance and anger with self-demeaning.

It is prohibited for a believer to humiliate himself when confessing his sins to others. In some cases, it is permissible to tell others about one's mistakes, like to encourage them to repent or similar reasons.