Phone cuts off after a few seconds...

[Strange_Days]

Hi, this is my first post I'm fairly new to smartphones. I have a UTStarcom 6700 on TELUS and my problem is that when I make or receive a call within 5 seconds to 2 minutes into the call either the line goes dead or I hear a busy signal and I can no longer hear the person I'm talking to and they can't hear me. It still shows me connected. I even installed helmi_C ROM update to WM6 but the problem remains. Any help would be greatly appreciated otherwise I have a brick that's costing me $50 a month...Thanks