The interest rate is around 28.8% and it will continue to accrue.
Do not give them details about where you work; MJR does sue on credit card debt so you may end up getting sued and with a garnishment if you aren't careful. Read this article for some good tips to prepare you for some of the stories these bill collectors will tell you:
http://www.totaldebtfreedom.ca/articles/article_13.htm
Original creditors don't get involved much once they send it to a collection agency. They will only pull it back if you have been very poorly mishandled and have recorded proof of it ( IE sworn at, called names etc. )
You could try and approach Canadian Tire and offer your payments but quite often they just refer you back to the collection agency. I know you think your reason for falling behind might be unique but everyone has a reason for falling behind in their payments, not many people do it on purpose so your story isn't likely to pull on any preverbal heart strings back at Canadian Tires head office.
You could also settle for much less then what they offered you if you have access to a lump sum of money today, otherwise you could sign up for a debt settlement plan like ours over 36 months and pay about $200/m which would include the debt negotiation fee.
You do have options; don't let them bully you around.