Returns a list of contract cancellation requests if any are found, returns an empty list or an error otherwise.
Response example

{
    "object": "list",
    "data": [
        {
            "object": "contract_cancellation_request",
            "id": "019282d4-a2b6-4da8-bc4b-a59491caccb5",
            "contract_id": "28e0968e-2b44-42ca-ae51-4d31962b591c",
            "reason": "already_insured",
            "final_reason": null,
            "other_reason": null,
            "reason_event_date": "2023-09-01T15:07:56.572316Z",
            "status": "pending",
            "created_at": "2023-12-15T17:23:13.603399Z",
            "updated_at": "2023-12-15T17:23:13.603399Z",
            "source": "policyholder",
            "refund_amount": 0,  
            "refund_currency": "EUR"
        },
        {
            "object": "contract_cancellation_request",
            "id": "2e091f22-ea16-415d-8a40-595082e8ceea",
            "contract_id": "28e0968e-2b44-42ca-ae51-4d31962b591c",
            "reason": "other",
            "final_reason": "already_insured",
            "other_reason": "a reason given by the customer",
            "reason_event_date": "2023-09-01T15:07:56.572316Z",
            "status": "approved",
            "created_at": "2023-12-16T17:21:24.823143Z",
            "updated_at": "2023-12-17T17:21:24.823143Z",
            "source": "policyholder",
            "refund_amount": 1000,  
            "refund_currency": "EUR"
        }
    ]
}