If I understand correctly 60 units = 0.5ml which would be 2.5mg if they mix 2ml with 10mg of peptide. So if you divide that by half you get around 1.25mg for 30 units on the pen. 1 unit on your pen = 10000/240=41,6mcg so sounds like you just didn't inject enough.
That said, I would not be buying pre-mixed peptides... or pens. Due to multiple reasons like peptide degradation and price.
