I think the refresh time is called TTL (Time To Live) where they are looking but it might be too late to make a difference
... the time to reduce that was several days before the dns switchover, but it is worth a try if they will do it.
I use other dns servers that are not from the internet service provider...
I am not with Cogeco; I am with http://www.start.ca
(a *very fine* ISP by the way, that runs on top of Rogers Cable infrastructure - tell them I sent you and I'll get a credit!!
- no long term contract;
- you buy the DOCSIS D3 modem
- etc - LOL)