Since you have been a customer from September 2013, you are considered a legacy or grandfathered customer, on a price-protected plan.
As a grandfathered customer, you are not entitled to any credits, discounts, rewards, etc.
To become eligible for them, you would need to leave your grandfathered plan for one of the new ones, which are more expensive. If you leave a grandfathered plan, you CANNOT return to one, even if you change your mind.
If you choose a 90-day plan with Auto-Pay, you should see a significant saving on your second bill statement once Royalty and Auto-Pay Rewards kick in; I'm seeing my bills have become a lot cheaper compared to the grandfathered plan that I used to have before Telus took over. Oh don't forget about Referral Rewards and participating in these PM Community Forums to get Bravos that translate to Rewards! I'm saving so much money by referring Friends and Family over!