New Vehicle Purchase

I recently bought a new Ford Ecosport Titanium 1.5 TDCI from Motomid Middelburg. At first the service was very good and the sales consultant, Natasha Nagel was very helpful. After I asked the sales consultant to go ahead with the purchase, I called her and asked her to add a towbar to the deal before I signed the contract. She agreed that she would add the towbar, but that there was no stock at that stage. After signing the contract I realized that the towbar was not added as I had requested. I queried this with Natasha, after a week she responded via email saying that she could not add the towbar to the deal as there was no stock and she did not have a price for the towbar. But a month earlier my friend bought the same vehicle and her towbar was included (although she also did not receive the towbar). I called around to find out about a towbar from other Ford Dealers and I was told that Allen Joss Ford can do the installation for me. They order the towbar from Ford SA and the installation is done at the Ford Dealership, I was also told that there is stock available. Motomid told me that only Ford parts can be used and only a Ford dealership can do the installation otherwise I would lose the warranty on my vehicle. Allen Joss Ford told me that my warranty would still be intact as I have used a Ford Dealership. It seems that once the deal is done and the commission paid, customer service seems to dwindle. Why is it that one Ford dealership can do what is necessary, but another doesn't seem to care.