"так и не" meaning in Russian

{
  "forms": [
    {
      "form": "tak i ne",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "так и не"
      },
      "expansion": "так и не • (tak i ne)",
      "name": "ru-adv"
    }
  ],
  "lang": "Russian",
  "lang_code": "ru",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Russian entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "english": "Moscow has never responded to Washington's demands.",
          "roman": "Moskvá tak i ne otvétila na trébovanija Vašingtóna.",
          "text": "Москва́ так и не отве́тила на тре́бования Вашингто́на.",
          "type": "example"
        }
      ],
      "glosses": [
        "never (did)"
      ],
      "id": "en-так_и_не-ru-adv-X0KhEpIk",
      "links": [
        [
          "never",
          "never"
        ]
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[tak i nʲɪ]"
    },
    {
      "ipa": "[tak ɨ nʲɪ]"
    }
  ],
  "word": "так и не"
}

{
  "forms": [
    {
      "form": "tak i ne",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "так и не"
      },
      "expansion": "так и не • (tak i ne)",
      "name": "ru-adv"
    }
  ],
  "lang": "Russian",
  "lang_code": "ru",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        "Russian adverbs",
        "Russian entries with incorrect language header",
        "Russian lemmas",
        "Russian multiword terms",
        "Russian terms with IPA pronunciation",
        "Russian terms with redundant head parameter",
        "Russian terms with usage examples"
      ],
      "examples": [
        {
          "english": "Moscow has never responded to Washington's demands.",
          "roman": "Moskvá tak i ne otvétila na trébovanija Vašingtóna.",
          "text": "Москва́ так и не отве́тила на тре́бования Вашингто́на.",
          "type": "example"
        }
      ],
      "glosses": [
        "never (did)"
      ],
      "links": [
        [
          "never",
          "never"
        ]
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[tak i nʲɪ]"
    },
    {
      "ipa": "[tak ɨ nʲɪ]"
    }
  ],
  "word": "так и не"
}