I want a discount on a new club term memebership, as the last time I bought one I was injured and out of action for half of the duration.
How did you get your injury?
I got an injury after an indoor soccer game
While it sucks you got injured, it's not the club's responsibility to compensate you for it. You don't deserve special treatment apart compared to others who bought the exact same thing as you. Just buy a new membership and play responsibly.
You don't understand, I was going to become the best indoor soccer player and now I can't.
Even so, the club does not and cannot take responsibility for the actions of players.  Since your injury resulted from a game, it is a risk that you took on by playing there, and legally the club does not owe you anything for it.