Sweet wine was sour!

I usually purchase the box of natural sweet red wine, on my last purchase, I found the wine to be sour. The box also swelled up (pics can be provided). I did complain to customer care, and they replaced the box of wine. I opened this box of wine a month later, on my birthday, only to find that this box of wine was also sour! I was very embarrassed as i had offered this wine to my guests. I am extremely disappointed in your quality and I did email customer care again just to inform them, I also stated i did not want another replacement box. Its been a week since my email was read, and completely ignored. No acknowledgement of my mail, no apology, no response at all!