I purchased some silver bars from the perth mint today (first...

I purchased some silver bars from the perth mint today (first time doing so). I gave my details and what not and was told I would be emailed my invoice in order to pay (my order was under 2k so no need to sign and fax back).

My question is to anyone who has done the same thing, how long did the email take to arrive?? I have been waiting 2 hours for it now, ordered at work and just got home then and no invoice.