Cordless phone

A few months ago I bought a Panasonic cordless phone. Just a month later it stopped working for short times. No dialing tone. When I plugged in a different phone, there was a dialing tone. But the problems was not continuous, only at times. But it became more and more. I returned it to the branch and they tested it. At that time it worked. After trying to explain to the manager on duty that it is not a continuous problem, Maurice agreed to exchange it for me. But now the new one also is a problem. Maurice said that it has to be sent in to Panasonic. But I know it is the same problem as the previous one and would prefer just to return it.