Poor customer service from Heineken(Windhoek Lager)

About 2 to 3 month ago we purchased a case of Windhoek lager from SPAR Tops. We've unpacked the case in the fridge and only opened a bottle later. After opening the bottle and my husband took a sip he realised that something was wrong with the beer as it tasted like vinegar. When we looked at the contents of the bottle we saw stuff floating around in the bottle. looked like tablets dissolving. We immediately took it back to SPAR Tops and were we informed to lay a complaint with Heineken customer care. This was done and we were informed that the sample along with a closed bottle of the same batch will be collected. As we already gave the bottle back to SPAR Tops we informed Heineken to collect it from there. I went to SPAR Tops and informed the manager that Heineken will send a courier company to come and collet the two bottles. The one that was opened was closed again with the top so nothing can fall out. After a week the samples was collected from SPAR Tops. I kept on having to following up with the customer care department to find out what the results was. Eventually after numerous mails we were informed by the customer care services that the test results was received and that the beer was flat due numerous possibilities. I then send them a message with the pictures of the bottle we took and informed them that the issue was not that the beer was flat but the particles that was floating around in the bottle. I was then informed that the bottle that was tested is not the same as the bottle in the picture. Asking them what happened to the sample that was send back they told me that they have to investigate. I followed this up after almost 2 weeks just to be informed that they found out the sample bottle broke. So we will never know what was in that bottle. How does a courier company transport goods without ensuring that it is safely packed so it will not break. Unacceptable.