Nextra Broadband www.nextraworld.com - Not get the security refund

I opt the nextra broadband connection at my home from Dec ****- May ****, after that I told to the vendor that I want to discontinue this broadband connection so you can collect all your assets and refund my security amount which you took at the time of installing the connection, security amount was ****rs at that time and from that day he was not responding my calls and when I call him from different numbers so he told that company is not paying the security amount and then he disconnect the call. I want to complaint against him and the company as well.