Mr Shopper PS4 controller faulty

I ordered a PS4, it got delivered on time. after a few days of using it I noticed one of the controllers is faulty and the touch pad does not seem to work properly. I contacted Mr Shopper and they said I would have to return the whole console and not just the controller because they have to take it back to the suppliers. I just want them to replace the controller. But they are not willing to help me that way. It is a bit frustrating because if I go on with the return I will be left with no console until the return process is done.