Detailed bill review

Is there anyway to have a proper detail review or my bill properly escalated so over payment can be received back . My bill was set but some things have went bad with my bill, i called in but it seems theres no explanation, to why just the contract is no longer offered do they cannot fix it. I tried to go back down to unlimited and thats not “include” its s 25$ add on. Well i was told today that she will not add it on and they will keep my bill high.