You will have to contact Xbox/PlayStation for a refund if you bought it digitally. However I'm not sure if they issue refunds if you are over a certain time period/too much time played.
I am closing this as we cannot help further with this request …
Complaining about it here won't do anything, if you report the player to EA that would be the better approach. You can learn how to do so here: https://help.ea.com/en-ca/help/faq/report-players-for-cheating-abuse-and-harassment/
Re installing wouldn't delete any multiplayer data (It would only do that for some single player games that don't do cloud storage) but basically every multiplayer game out there your data is stored online.