On Koodo Prepaid, the long distance is as follows,
1 Canadian minutes uses 1 minute from the pool
1 US minutes uses 2 minutes from the pool
1 International minute uses 5 minute from the pool
If this could be implemented on the price plans instead of adding overages on the bill. so if the plan has 1000 minutes, that would be 500 minutes if they call US and 250 minutes if they call international.
If the plans are not enough they can add more minutes to their bucket.
If the plans are unlimited calling within canada, they can add the minutes separately only for international. So lets say what they had on Public Mobile. $20 for 1000 International minutes or 2500 USA minutes. and disregard the Canadian minutes since their plan includes unlimited calling.