Is there a bus line between Halifax, NS and Quebec City or Montreal?

I love the train, but I'm trying to look at alternatives. Acadian Lines seems to only have service in the Maritimes. Orleans Express seems to be only in Quebec. Greyhound's website claims to have stops in both provinces, but they tell me they don't service the route pretty much ever. Help?
Even if you know a bus that goes between the provinces of New Brunswick and Quebec, that would help a lot!

Please provide a link, or at least a company name. Thanks!

Hi there

is this who you called for the info? they are the Greyhound agent in Halifax

ACADIAN LINES LTD
1161 HOLLIS STREET
Halifax, NS B3K5M1
902-454-9321

and it should get you to here:

TERMINUS D'AUTOBUS DE LA
GARE DU PALAIS
320, RUE ABRAHHAM-MARTIN
Quebec, PQ G1K8N2
418-525-3000

I agree the Greyhound website and phone lines are not helpful

we had a similar issue last year with them
we finally had to call the head office in Calgary -- there's this number

Fare and schedule information
1-800-661-TRIP (8747)

and get the correct info and tell them what the local agent had been saying -- which was incorrect -- before it finally got sorted properly and the correct fare charged, etc