The OP's image has been edited to remove the playername and cover some of the more obnoxious language. "Naming and Shaming" is not allowed per our Community Code of Conduct, even when someone has so obviously done something in the wrong.
Customer Support Tickets are the path to getting such issues dealt with. Thank you for creating Ticket #144090542.
A review of the offender's account shows language like the above was used regularly in and out of battle for more than the last two months, but your CS Ticket was the first one filed. This is a notice to all players that CS Tickets are very important, and please do not assume that others have done so before.
In the future, when the issues are egregious, please make a CS Ticket and then message myself or one of the other Community Managers to let us know about the situation.