Poor service and aftersales

I had my Iphone battery replaced at the weFix branch at Cape Gate, less than a month later the battery died completely. I took the phone to their Tygervalley branch where they replaced it under guarantee, during the course of the next two months I was back there twice with the same issue, the battery is completely dead. I went there today for the third time with the same issue only for then to tell me that the battery is now out of guarantee. In other words there new battery which they replaced carry no guarantee, even though there are clearly very serious issues with their new batteries for I have gone through 3 batteries in 5 months. this seems like a wat to get out of replacing poor quality batteries being supp**** by weFix.