Adidas supposedly has no managers

I purchased a Manchester united jersey from Adidas, the jersey came with a stain on it. After days and weeks of trying to report it with no customer feed back I reached out to them on Instagram and shared the issue along with the pictures of the stained jersey. The person handling their Instagram account advised that they have forwarded on my complaint, I also kept the person updated for days after that I still haven't got the response. Eventually Adidas does respond saying it's over 6 months and they are unable to do anything the return period has expired. When requested to get into contact with a manager I was told there are no managers for them to put me through to.

They won't replace the jersey or offer up a discount to compensate me for the cleaning I had to do to get the stains out.