Pivot and Crosstab Dynamic in Sql Server

DECLARE @cols AS NVARCHAR(MAX),
    @query  AS NVARCHAR(MAX)

select @cols = STUFF((SELECT  ',' + QUOTENAME(D.DESTINATION)
                    from BillingDetail B inner join BillingDialDestinationtranz D on B.CDid=D.TDid
                    group by D.DESTINATION
                    order by D.DESTINATION
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)')
        ,1,1,'')

set @query = 'SELECT Carrier, ' + @cols + ' ,CCost
            from
            (
              select  CarrierDD.DESTINATION,C.CarrierName as Carrier,round(sum(((cast(BM.CallDuration  as real)))*BM.CRates )/sum(BM.CallDuration),6) as CRates,round(sum(BM.CallDuration) ,4)  as Minutes,round(sum(((cast(BM.CallDuration  as real)))*BM.CRates ),4 ) as CCost
             from [4BSales].[dbo].[BillingDetail]  as  BM   inner join [4BSales].[dbo].BillingCarrier C on BM.CarrierId= C.CarrierId
left outer   join [4BSales].[dbo].BillingDialDestinationtranz CarrierDD on BM.CDid=CarrierDD.TDid
left outer join [4BSales].[dbo].BillingDialDestinationtranz VendorDD on BM.VDid=VendorDD.TDid
left outer join [4BSales].[dbo].BillingCarrier v on BM.vendorid= V.CarrierId
group by C.CarrierName,CarrierDD.DESTINATION
            ) x
            pivot
            (
                sum(CRates)
                for DESTINATION in (' + @cols + ')
            ) p '

execute(@query)