There are a few ways you can get in touch with Audible customer support.
The best way to reach out is through their customer support page on Amazon (link: https://www.amazon.com/gp/help/customer/contact-us/anonymous-contact-us.html? CD3EFCEF-1FBD-4DF8-B0C5-F84B3842C1F3&ref_=amazon_help_contact_us). From there, you can select the category that best fits your inquiry, and then choose either to call them or chat with them.
Another way to get in touch is through their email support page (link: https://www.audible.com/customer-service). This is a less direct way of getting in touch, but sometimes it can be helpful to send a longer, more detailed message this way.
Finally, you can also reach out through their social media pages. Audible has pages on both Facebook (link: https://www.facebook.com/audible/) and Twitter (link: https://twitter.com/audible_com). These can be good places to ask quick questions or get general customer service help.