Whoever told you that is bogus. Did you see a Speakout display? Virtually all 7-11's have some sort of prepaid phone display. Some show just the cards, and some have phones. They will also have top up cards from lots of other prepaid companies as well.
I would report the clerk to Speakout. Many clerks are clueless about Speakout. Give them an email and see what they say.
What's so unbelievable about this? So he was a new guy in training and didn't know everything... happens often in retail (especially here in Calgary).
He never said he was a new guy in training. He might have been working there a shile. Maybe he was a clerk who was just lazy and didn't want to help a customer. I get them at my 7-11 as well.