Going bankrupt or filing a consumer proposal for $3,500.00 worth of debt makes no sense. The fees would be too high. I was assuming that there were other debts as well. In terms of dealing with this creditor your settlement of $150.00 per month sounds pretty good. I would recommend always communicating with the creditor in writing and keeping copies of everything. That way if you end up in court you will be able to show the judge that you have attempted to deal with the creditor.
Good Luck,
Chris