car oil not changed

As a woman my husband send me to car service city for car service and maybe because I am a pregnant woman the people there, took advantage of the situation. And did not do what they are suppose to do. They even charge me for things I did not know about, thing my husband did not ask for. And I paid for the service. On the very same night when I get home he checked what they did, he found out they did not change the oil inside the engine. He then took the car to them in the morning so that they can do it, but they refuse to do and the manager said he is not going to talk to him. And now we have to buy an oil for the car and spend the money that we don't have because of them.