Why do Fiverr sellers not respond to personal messages when you have an active order with them?

[Btaliat]

It is not an uncommon case for the freelancers to feel neglected by the clients. In some cases, this may not be done intentionally. Clients may just be busy to attend to the mails and calls. Though this sounds weak because it is possible for the clients to be intentionally doing that, maybe because the freelancers are not polite in their mails. It is always as well possible for the clients not to be available truly. What do you think freelancers need to do ?