Hey guys! Great news. As a newish Circle customer (joined about a month ago) I was limited to $100 a week until they updated their TOS and raised everyone's limit. Still, though $300 didn't really suffice, so I put in three messages to support over the last couple of weeks and maxed out my $300 limit three times. I logged in to Circle today and saw that my instant limit was raised to $3,000 instant.
TL;DR - Have faith in Circle limit increases!!
This happened to me in the past few days as well, I had left tickets to support for other questions and then would slip in that I would like my limit increased, they said they would put a note on my account as I bought more and more coins. Log in yesterday and my limit has been increased from $300-3,000. I did the happy dance.