Nextra Teleservices — Very poor service

There is not a single day when my internet dont disturb. And there is no way to contact customer care representative. I called and waited till 30 mins and after that phone hang off automatically.
I have written mail serveral times. No one respond.
I just want my money back that i paid as security deposit. I don't want to continue this worst service any more. I have all the phone call recording that i tried.