Huna is early and small, so support is a person reading an email rather than a help desk. That means slower than a big company, but you get an actual answer.
If somebody is bothering you, do not wait for email. Both of these are in the app and work immediately:
Blocking and reporting are separate. Reporting on its own does not stop someone contacting you, so if that is what you need, block first.
Deleting your account. Settings, in the app. You have 30 days to change your mind, and your username stays reserved for you during that window. After 30 days it is gone and cannot be recovered.
Getting your data. There is an export in Settings that gives you your profile, check-ins, photos, friendships and messages in a machine-readable format.
Changing your username. Once every 30 days. Your display name can be changed any time.
Reports are read within 24 hours. Email gets a reply as soon as somebody can get to it, which is usually within a day or two but is not a guarantee at this stage. If something is urgent and involves someone's safety, say so in the subject line.