The whole DTT/DCC/Cafe Racer TV self-congratulatory, mutual back-pat, hairdo and fashion society is a bad joke that has little or nothing to do with motorcycles. Consider buying from someone else next time.
Putting that aside, there are two immediate possible problems that occur to me:
1. If these are the front signals, the stockers had two 'hot' wires, and one frame ground (Often the housing is metal and grounds to the frame directly, without the need for a third 'ground' wire, but I don't know whether this is the case with your machine). If this is the case, and the signals you bought have two wires intended for use as one 'hot' and one 'ground', you are wiring it wrong. Fix that.
2. It is also possible that the stock flasher relay needs a bulb of sufficient wattage to flip it. This is a 'load' relay. If this is the problem, you can replace it with a no-load relay, and it should work OK.