Apps You Need — delivery of my mobile phone

I gave my cell phone to the service centre through the apps you need insurance for liquid damage. According to the insurance companies guidelines, my cell phone should've been returned back to me 30 days after it has been received at the service centre. My mobile was received at 28 april 2017 and it still hasn't been returned back to me. I called numerous times but everytime their employees were busy and nobody would answer my call. I posted complaints on their website. They responded to three of my complaints but after that i posted 5 more times but they haven't even responded to it. I want my phone back and they're doing nothing about it.