A little confusing because first you said you want to open an account with a Canadian online broker than you said you emailed your broker name VB. I will assumed the VB broker is American considering you implied you do not have a Canadian broker.
Why not just call a Canadian broker because they all have telephone numbers....make sure they understand you're talking about trading "U.S. stocks" and not "Canadian stocks" ?
Next, if they said there's no PDT rule for Canadian account holders trading U.S. stocks...ask them to point you to the location on their website that states such or ask for them to send you their literature about such or email it to you.
Last thing you want is a Canadian broker sales rep misunderstand your question and say something like "I thought you were talking about Canadian stocks".