Waiting 3 months for a part

I have called the spares department of John Williams Motors for an oil pump for a Chrysler Voyeger of mine, they said if I pay in the amount due they will order the pump and that it will be there in 2 weeks time, but it has been 3 months now and every time they just shrug their shoulders and say that it hasn't come yet, without any clear indication of whether the part will be there, I have already spoken with the manager as well and after many false promises am still waiting for a reply from him. I am waiting now for the part since 15 Oktober 2015.