Archiving didn't work for me for first 3 days, so I sent an email, no response. Followed up 2 days later, no response. Contacted on Twitter, got a response that it'll be looked into, but it wasn't solved. Contacted on Twitter again 3 days later, no response. Finally, it did start working a few days later but stopped again.
I emailed again, no response. Followed up 4 days later, no response. Contacted on Twitter, no response. Emailed on founder's email 2 days later, no response. Another contact on Twitter, no response. I did get a response when I send a DM that the lack of response was due to huge impending work.
It's completely possible that the work was indeed huge and I was growing impatient (for that, I apologise), but I wasn't expecting that the problem is solved immediately but just how and when it'll be solved, that's all.
I didn't send any messages after that and it seems issues are slowly getting fixed. There are still issues with accessing the archived links, but I feel there won't be any point in reporting them. Pinboard is an excellent service that I use every day, but I wish there was more effort to make users feel less frustrated.