Logic Apps - Json Arrays and Response

Question

Please help. What I am trying to achieve is providing a Logic App back end to an API.

The API is to look up values within database to generate a quote.

The flow is to look up a service to see if we have an active service. If so, it then looks up the selling rates and cost rates for that service.

The sell rate is based on the cost rate so need to retrieve both and supply in response to work out the sell rate.

For Each Service I am getting the Selling Charges then for each Selling Charge I am getting the rate calculation

I am appending to array. However, my outcome is:

[
  {
    "ChargeCode": "Carge2",
    "ChargeDescription": "",
    "ChargesCalculation": [
      {
        "base": null,
        "break": null,
        "calculationType": "COS",
        "currency": "GBP",
        "max": null,
        "min": null,
        "rate": 1000
      }
    ],
    "CostsCalculation": [
      {
        "base": null,
        "break": null,
        "calculationType": "CTN",
        "currency": "USD",
        "max": null,
        "min": null,
        "rate": 27000
      }
    ],
    "Currency": "USD"
  }
]

[
  {
    "ChargeCode": "Charge1",
    "ChargeDescription": "",
    "ChargesCalculation": [
      {
        "base": null,
        "break": null,
        "calculationType": "FLT",
        "currency": "GBP",
        "max": null,
        "min": null,
        "rate": 50
      }
    ],
    "CostsCalculation": [
      {
        "base": null,
        "break": null,
        "calculationType": "CTN",
        "currency": "USD",
        "max": null,
        "min": null,
        "rate": 27000
      }
    ],
    "Currency": "USD"
  }
]

The second loop has no costs so just need a blank array rather than copying the same amount