The OP doesn't state he wants $1000 so let's not assume that.

Writing the letter is good - LH should train staff on avoiding this mistake on certain routes (including any to India) where these options are offered as a matter of course - and no special meal needs to be ordered (all airlines I know offer Indian veg meals on flights to India).

On the other hand - while it may cause personal distress - the religious implication would be very limited. So writing the letter and avoiding a recurrence is enough and the OP should move on.