FFA, I suggest that you first call the competitors to find out what kind of a deal they will give you before calling your current providers. Then you can ask your current providers to match the competitors' best offers, and threaten to bail if they won't.
I did this two months ago with my ISP, and cut my monthly bill $15.00, from $44.99 to $29.99.
PS - This may not be relevant to you, but I make all my calls from home using my magicJack. The initial cost is only $39.99 for the device and one year's service, and then after the first year the cost is only $19.99 per year for US calls. I don't know if Canada calls are included for free.