I got a call from them too. When I called back I heard "You have reached Cytel" and then the line disconnected. Tried it twice with same result. Don't know who they are.
I was speaking with an internet tech at what I thought was Bell. The line dropped and the number which showed on my phone on a call back was 416-350-5250. When I called the number back it answered as Cytel (http://cytelsolutions.com/) which appears to be an internet tech solutions company.
It appears Bell farms out their Internet technical solutions to this company.