Manager attacks customer on social media

After purchasing sour milk from Viva Slurry. I returned it to find that all the other milk was from the same batch. I took the same quantity of milk in smaller containers and was forced to swipe again as there was a slight price difference which I think they could've reimbursed me for my effort to drive up and down. Further more, there is a liquor store as part of the garage, which I have no problem with. As I walked out of the garage the people that are allowed to drink in the parking of the premises leaned on my vehicle like it's a resting bench, which really ****ed me off. I have laid previous complains via private messages to them on their Facebook page regarding previous incidents without receiving any response. So I took today's matter in my own hands and posted on my personal wall that the service of the garage has gone down significantly. After which the so called general manager of the garage took me on on social media and attacking me personally. They took it so far as to call my relatives at 22:15 in the evening. I'm also not the first client to complain about this garage and the service here. As we are a small community I thrive to support our people, but with incidents like this we cant build anything positive. I have filled up at other Viva branches before and had the best experiences unlike before. So I think we can agree that there is a standard towards Viva thrives. I will be pleased to get a call from Mr. Qwie Kruger to hear how this matter will be handled.