Anyone heard of Sleektel?

I received a telemarketing call on Friday from a person from Sleektel, offering me a discount on my Telstra phone bill. Normally I ignore these sorts of things straight away but I looked up their website while they were talking away and everything seemed legit and they had heaps of info on me - name, address birth date etc (not that that's hard to find these days). I agreed to their deal on the basis that there was a cooling off period (and also I was thinking of haggling with Telstra).

Anyway, I'm just wondering if anyone here has heard of or had any dealings with them? Their deal was that they bill me at a substantial discount to what Telstra charge, but all my phone & internet stays with Telstra. Seems like a strange arrangement and probably falls in the "to good to be true bucket".

Thanks