Sending a letter of demand is nothing to be alarmed. This may be a indimidation tactic as court had already granted enjoining order. In commercial world for a day millions of letters of demand send. Only handful succeed in litigation, some end up even paying hefty costs. Eg our own headging case in UK High Court, which was lost and appealed we lost both with hefty cost to other side. We had some cases here regarding same , locally too some interim orders where also made but I do not know what happened to local cases. Both counsel who appeared for CPC are holding very high positions now. One is in multilateral organization other apex local body, they were both very capable counsel.