Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Customer service not available for this product!

Try contacting Superswitch (Blackstone) regarding a problem with their product. No response. They have no customer service. It's hard to believe that some manufacturers (in this case the US reps) only want to sell their product and if a problem arises, they hide. Check the warrantee from the seller. After that, you're on your own.