Poor service from VW

On the 28th of December 2017 ,I brought my car for 105 000kms ,at that time the malleage was 107 000 kms ,I was told that the oil an oil filter was changed and to my surprise last week the car has shown a sign that the oil needs to be changed ,when my husband checked the engen was completely dry there was absolutely no oil at oil in the vehicle ,and I had two fill up with 2 tins ,I have just called David Villet who was my service advisor he said the oil was definitely changed and I have asked him if it's a norm for the oil to be filled before it's due for service and he said the sign has popped in because I brought the car at 107 which I feel that's nonsense ,I have never experienced such thing even when I brought the car a bit later ,ever since I have started servicing my car I have never received the old parts that have.been changed which makes me doubt if they do the thorough service or they take chances because they know as females we don't have much experience ?he said I must bring the car for service again and they will charge me which is unfair ,should any damages occur in my car VW Will be liable for them,and I will report them to my company as this s a company car,