I thought having 200 minutes' airtime was more than I needed, turns out this month only (and I have been with Koodo for 4 years), I passed my airtime and did not realize. This month cost me almost three times my plan, which is very frustrating considering this never happens to me because I am conscientious and a good customer.
I am sure you receive complaints of customers who passed their airtime and think their extra fees are way too expensive everyday. I was informed that it is possible to receive a text message when 90% of your data has been used (or something of the like), why not apply this also to the airtime? This would differentiate Koodo from its competitors who probably don't do that, and your customers would not be unsatisfied from their experience.