I am sorry that the experience has been less than stellar. If you have the time you should call in to report the issue so it can get fixed. That would be my advice for you if you have not done so already.
I have read about a lot of problems with this device and a lot of it stems from the fact that the manufacturer is a cheap Chinese manufacturer at that and not all OBD2 ports are fully compatible with this device.
I can almost assure you that the problem is with the device and not the car's diagnostic port.
Conversely I can attest to the fact that a good elm327 adapter can work properly with almost any port using the proper app and software. But if the hardware itself is flawed then there's no fixing the issue without replacing the device or opting for a different brand altogether.
However it should also be stated that the Verizon hum device has its fair share of problems as well.