I feel like every two years I need to call my carrier and complain if I want a decent deal. They will do things like upgrade my plan on their website to have 10 extra gigabytes of data but won’t upgrade me to it until I contact them. There’s also all the new member exclusive deals that I feel make it impractical to just sit on one plan for an extended period of time.
The answers here are interesting. If I don’t change my mobile plan after it expires (2 years) and it gets renewed automatically it will get more expensive for the same service. Actually, if you want to keep getting a decent price, the best way is to completely change provider every 2 years.