iPhone 6S Headphone Jack Problem

Hi Apple Community,

I have an iPhone 6S 64Gb around a year now. Usually, I use the original Apple pods which came in the box with my iPhone. Recently, I bought two new headphone (Razer and Skullcandy), once I just connected them to my iPhone it went crazy. Siri starts out of nowhere, the volume goes up and never goes down and the microphone is not working. I have to hold the phone near my mouth to speak through the iPhone's microphone at the bottom. Please notice that these two headphones (Razer - Skullcandy) are certified to be used with Apple products.

What should I do now? Please help.