To obtain a copy of a Sacramental record, you will need to contact the parish where you were baptized.
If your church has been merged into a new parish, the parish office should have all the baptism records. For instance, the Holy Name parish office has the baptism records for St Columba and St Joseph churches.
If the church were you were baptized is closed down and is not merged to another parish or does not exist anymore, contact the diocese of the former parish. The contact information for the dioceses of Canada can be found here on the CCCB website.
Or, you can always start by contacting the office at Holy Name parish.