Do you think I am right or wrong in this situation?

We went on vacation and had my 19 yr old daughter stay with her 3 younger brothers who are 12, 13, and 15...we left them with plenty of money, our car and had several ppl stopping in to check on them and had them on call in case of an emergency. While we were gone our hot water heater broke and we were bashed by my sister and her fiance because of it. They made some very harsh and unfair comments.....and my daughter joined in their tirade. I was to pay her 100.00 for looking after her brothers while we were gone and I decided after her disrespectful and nasty comments that until she could be respectful and appologize I wasn't paying her. Am I wrong? All I want her to do is appologize. She says she did what was asked of her, which is true. While we were gone she used our car to give her friends rides and to go to their houses...she was only to use it to go to school, work, and to the store. I just feel like she really really disrespected us and feel that there are consequences for your actions and I don't think it is too much to ask that she appologizes. Am I wrong as a parent to not pay her until this happens? I would like to note....we do take an adult vacation once a year and we take a vacation with the kids in the summer months just thought I would mention that as that too was brought up in the tirade.