Am I being ripped off or just ripped off?

I bought a little daihatsu charade a mth ago. It hadhad a new engine put in and and driven for 800km. Within a day the starter motor burned out. The guy who sold it to me replaced it. Within 3 days it burned out. He replaced it again.2 days later it burned out. This time my husband offered to pay half to make sure a new rather than rebuilt starter was put in. A week later it burned out. The mechanic /guy who sold it to us now says it happened because the new key we had made was faulty and causing the starter motor to stay engaged. That would make sens eto me IF that had been the key used all the time but the first 2 burnt out while using the original car key. His theory on that is that the 1st two were rebuilt and bad starters, the 3rd and 4th were because of the key and now wants 200 dollars -which we don't have to repair it so essentially we are going to have to write it off and take the loss. Does any of his reasoning make sense to you? I wish I could make a donation but we are broke