unfair treatment and inconvenience

My car has been with VW Nelspruit(alan Hudson) for a month now, for 2 weeks they have told me they have ordered an engine. the waiting period was 2 weeks and now they keep changing dates, they are adding another two weeks. I have requested courtesy car because part of my employment is to be mobile. they said they do not have courtesy car the only thing that they can assist me with is a hired car which also needs my credit card, I do not have credit card which means I cant be assisted for the delay they are causing me. I feel this is unfair and because they need to hire me a car under their details since they cannot provide me with a courtesy car. my job is now at stake as I can no longer meet the employer's requirements and condition of employment.