This sucks man, at least this only cost you potential earnings (that it sounds like you weren’t pursuing) vs any actual money.
I wonder if in theory, should you want to, there’d be any legal recourse.
As someone who grew up in India, this practice is actually quite common and not exactly frowned up. When you have multiple products that perform similar functions, whoever can sell them the best will gain market dominance.
OP did not pursue the monetization path chosen by his competitor and lost out only on potential income, this might be a good lesson in entrepreneurship and IP management.