If a $100 gift card is given to new customers, then existing customers should also receive this! Do I have to switch to a new phone company? $100 bonus for LG G3 - only for new customers.
There is a current promotion with Gift Cards available on upgrades as well! It's available at Best Buy across Canada as well as Walmart (Mobile Section). Koodo is always looking out for both current customers and future customers. Go check them out, I would specifically wait (if it's Best Buy) until September 3, 2015 as they have a VIP sale and the Gift Cards may be higher!