售后单退款金额与实际退款金额不一致？

售后单号：

2000002468828209 

和客户协商退单金额是300，接口返回的金额是400，请查证

{

  "reason": "10000581",

  "create_time": 1761232710,

  "openid": "oI3fj7AWn1c8490U5gQzMGMzM5Q0",

  "refund_info": {

    "amount": 40000,

    "platform_discount_return_amount": 0

  },

  "reason_text": "材质/面料/品牌与描述不符",

  "product_info": {

    "gift_product_list": [],

    "product_id": "10000233879473",

    "voucher_list": [],

    "count": 1,

    "sku_id": "3472860951",

    "fast_refund": false

  },

  "type": "REFUND",

  "compensation_liability_amount": 0,

  "after_sale_order_id": "2000002468828209",

  "merchant_upload_info": {

    "refund_certificates": [],

    "reject_reason": ""

  },

  "complaint_id": "0",

  "gen_scene": 0,

  "update_time": 1761232711,

  "refund_resp": {

    "ret": 0,

    "code": "",

    "message": ""

  },

  "return_info": {

    "delivery_name": "",

    "waybill_id": "",

    "delivery_id": ""

  },

  "details": {

    "prove_imgs": [],

    "tel_number": "13805868866",

    "media_id_list": [

      "GG4BISQz80rPsEIVG142VNX6bxDtBRBv8bqx2lqR5IOXWGR6Kepl3egXte9YND7EU_-DnOTm0t-6EYNYzw5Y_Q",

      "GG4BISQz80rPsEIVG142VPmICXa48zP5p9KeCKBQ0hfPZ2awC8LduADcR6zhD7ede4R4EV0YwxFCNs5-Gb2DSA"

    ],

    "desc": "按约定退款400元",

    "receive_product": true

  },

  "deadline": 1761362311,

  "event": 1,

  "order_id": "3731610521722299136",

  "status": "MERCHANT_PROCESSING"

}