My MeLuna ball style original cup is beginning to tear near the ball and on the side of the rim. I'm a little upset about it because I haven't even had it a year yet. I've always been paranoid about boiling it, so of course, I think this may have caused it. I've always tried to be careful while boiling it, making sure it didn't touch the bottom or the sides of the pan, but maybe the temperature was too high. What temperature would be safe for this cup? Would it be unsafe to continue using it?