Dowload XLSX file from UCM in VBCS Application

Hi,
I am trying to download a file from UCM in my VBCS application using SOAP API GET_FILE. Customer is using HCM cloud , reports generated in HCM are pushed to UCM.
The SOAP response has Doc Info and Attachment as Multipart.
I was able to download CSV files from the Attachment part, but getting issues while downloading XLSX files (files downloading but showing as corrupted)

URL :
https://xxxxxxxxxxxxxxxxxxxxxxxxxxxxx/idcws/GenericSoapPort

SOAP Request -

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ucm="http://www.oracle.com/UCM">

soapenv:Body
<ucm:GenericRequest webKey="cs">
<ucm:Service IdcService="GET_FILE">