I just want to say firstly that I am simply another seller here, I am not employed by Fiverr and the position of Moderator is voluntary and involves nothing more than some basic control over the forum as part of a team.
Anything I say here is simply my own opinion, not necessarily that of Fiverr or its staff.
The Fiverr Terms of Service explains how everything works here and the link to it can be found under “Legal” at the bottom of every page.
Regarding my original opinion - this was formed based on the info that you provided initially. If I have missed something or misunderstood then I apologize, however from what you have said all I can ascertain is that you placed an order, the seller delivered something, the order was marked as complete after 3 days. The fact that there was communication in between (in my opinion) is irrelevant. I have no problem criticizing people, I am one of the first to admit that there are some truly awful sellers here, however the system is there to be used. It is vital that the system is the same for everyone.
The “Resolution Center” is there to be used when necessary but there has to be some time frames involved or orders could never be closed and sellers would never get paid. The fact is that you didn’t use it and didn’t know the order would be marked as complete.
There is a few things that confuse me about what you have said.
The way it should work is that you select the seller you want (either through the search menu or from those who responded to you buyer request), you place an order, your buyer works on it and then delivers it, you accept it or request a revision. If you do neither then it is marked complete after 3 days.
From what you say it sounds like you placed a buyer request, many responded to it, you selected one and somehow an order was placed accidentally by you. (There is no way a seller could take a payment from you without your involvement. Payments are done securely through Paypal). You were not happy with what the seller sent to you but did not request a revision or cancellation. You simply said you didn’t want it and moved on to another seller.
If this is the case, it is unfortunate but the seller didn’t actually do anything wrong in my opinion. The delivered an order and you said you were unhappy and moved on. You did not take any action that was necessary to prevent the order being completed. The system then automatically marked it complete. The onus is on you to reject an order if necessary.