Welcome to the community!
Firstly, you should note these forums are community-driven and not intended as a venue for customer services. We would not have access to customers' accounts nor any details of your particular plan.
Sorry to hear your bill had unexpectedly increased. I don't think anyone likes price increases. I understand people like the notion that prices would never increase. Unfortunately, however, the cost of everything increases. At some point, those added costs would eventually increase the operating costs for companies. I don't think it's feasible for any business to not occasionally adjust their service/plan prices in response to rising operating costs.
You should note Fido / Rogers has increase the monthly fees for some customers' plans (see here and here). Fido usually provides notification of price increases in your bill a few months prior to any actual increase. Unfortunately, your plan appears to be one of the plans affected with the increase rate.
Since they switched from their subsidised plans (included cost of devices) to the Payment Program (separate device financing), I believe services are on a month-to-month basis. If you do have a contract, it would be for financing a device only. Services are charged separately. Since services are on a monthly basis, they are able to make changes provided they give customers sufficient notification (see Terms of Service; section 2c).
Hope this helps 😀
Cheers
