Ac-dimmer-module-8a

Message to the support.
I had a serious problem with the ac-dimmer-module-8a-1-channel-33v5v-logic-ac-400v-8a-4. It burned at first use. It was drived by the DimmerLink Controler (i2c mode). The dimmer module was connected to a 1200W water heater so about 5A max. After that, I changed and connected the Dimmerlink to the other Dimmer Module 16A I had, and I never faced problem until now. How do we do for the warranty please? I post here because I never got answer to my ticket from the support. Thanks.