Who to contact with, if no response from the seller

[gardentools2010]

Bought a set of LED lights for my car before going to overseas, came back after 3 months and put 6 lights on, 3 of them not working straight away, and one is flushing. I have passed the time to leave feedback, so i tried to contact the seller, no response. So what is the next step your folks do in this similar case

thanks in advance 

[padi*0409]

 you paid with Paypal open a dispute with them failing that if you paid with a credit card try a chargeback with your bank.

Note. Do not open a Paypal dispute and a chargeback at the same time or you'll lose on both.