Web based platform for Whatsapp bulk messaging

This is to be used occasionally to reach our clients in my own business. Must be easy to use and have attractive interface. 1- Multiple users 2- Customizable sender Name/ID 3- Able to upload contact list or individually (csv, txt,Vcard, excel) and recognize contacts the same way it does on mobile phone 4- Recognize if receiver doesn’t use Whatsapp and not send message 5- Reconcile new or uploaded contact number with existing list, detect duplicates and option to remove it. 6- Automatically generate extensive list of mobile numbers with codes or stating digits. 7- Interface with reports: total number of contacts, successfully sent, received, failed… 8- Option to select individual from list or input number to Send bulk or single 9- Allow attachments : images, videos, files 10- Pull thru messages 11- Unsubscribe option 12- Auto bulk send and time schedule for sending