Welcome to Justanswer.com, my name is Dustin.I'm sorry to hear about the issue you are having, I will do my best to help you resolve it.
Can the Seagate dashboard or the Seagate central discovery tool still see the Seagate central for any of your macs?
And besides time machine not working, can you view and access any of the files on the seagate central from any of the machines?
Understood.. Since you asked for a refund, I unfortunately cant provide further info..
But it sounds like you are on the right track.. Here is the refund link as you requested
If you change your mind or run into further issues and need assistance, you know where to find us.
Best of luck! And thank you for trying Justanswer.com
Dustin S.Senior Technician and Network Switching Systems Operator / Maintainer.