Srtipe downgrade

Если понимажает клиент подписку,она применяется в конце текущей подписки.

    $this->user->stripe()->subscriptionSchedules->update(
            'sub_sched_1KtsXdLueT3PfXuFDuOxZBAb',
            [
                'phases' => [
                    [
                        'start_date' => Carbon::parse($this->user->subscription()- 
      >created_at)->timestamp,
                        'end_date' => Carbon::parse($this->user->subscription()- 
  >created_at)->addDays(30)->timestamp,
                        'items' => [
                            [
                                'price' => $this->user->subscription()->stripe_price,
                            ]
                        ]
                    ],
                    [
                        'start_date' => Carbon::parse($this->user->subscription()->created_at)->addDays(30)->timestamp,
                        'items' => [
                            [
                                'price' => $request->plan,
                            ],
                        ]
                    ],
                ],
            ]

        );
    }

но мне страйп возвращает "message": "You can not modify the start date of the current phase." Не могу понять в чем причина.