What to do when Meter ID is not correct in usage data from Azure Billing Usage API

I am getting wrong Meter ID from Azure Usage Billing API. The exact response entry which is wrong is shown below. Note that it is text "1core" instead of a Guid. Therefore I can't find it's rate from the Rate Card API data. I also noticed that many of other properties like Resource Category are also null. This same entry repeats over various days.

Can anyone tell me why could this be? And also how should I treat this entry while trying to calculate the monthly bill?

{  
     "id":"/subscriptions/1a11aa11-5c9b-4c94-b875-b7b55af5d316/providers/Microsoft.Commerce/UsageAggregates/Daily_BRSDT_20160312_0000",
     "name":"Daily_BRSDT_20160312_0000",
     "type":"Microsoft.Commerce/UsageAggregate",
     "properties":{  
        "subscriptionId":"1a11aa11-5c9b-4c94-b875-b7b55af5d316",
        "usageStartTime":"2016-03-11T00:00:00+00:00",
        "usageEndTime":"2016-03-12T00:00:00+00:00",
        "instanceData":"{\"Microsoft.Resources\":{\"resourceUri\":\"/subscriptions/1a11aa11-5c9b-4c94-b875-b7b55af5d316/resourceGroups/OPENTEXT-RESOURCE/providers/Microsoft.Compute/virtualMachines/OpenText-Test01\",\"location\":\"eastus\",\"partNumber\":\"1AA1A1X2X3J6Z5CTGYDP3JINVU3KI3SQMOF62ZDVD4WHVECLMDI72J5ZD42PMNW4IEDRHARE6JZZ3LHM65KKHRDNLEL5EOQALXEFO5A\",\"orderNumber\":\"a1aa1111-bed9-4451-bdf7-274f05f35201\",\"additionalInfo\":{\"ImageType\":\"\",\"ServiceType\":\"Standard_A1\",\"VMName\":\"\",\"UsageType\":\"ComputeHR_SW\"}}}",
        "meterId":"1core",
        "infoFields":{  

        },
        "quantity":8.0
     }
  },

Solution

I got an official response from MSFT that this particular record is from the resources related to 3rd party marketplace items. Unfortunately, these 3rd party marketplace items do not implement the Billing API, which is in preview right now. If you are also seeing this kind of records, please ignore these records and just highlight in the report that 3rd party marketplace resources may be missing in the billing report. Please note that this may change in near future, though there is no date on this.