You may want to talk to the representative from Univerty of Ottawa's legal clinic. They provide legal advices on tenant issues and other legal matters for free, or a small fee based on cost recovery. The hours and address can be found inside the link. http://www.uottawa.ca/associations/clinic/main_en.htm
There are absolute no credit problems that will affect your future immigration application. Minto just want money from you. I highly recommend you to talk to U of Ottawa's student legal representative to minimize the damage.