Infinity deep cycle battery

Infinity Battery pinetown and head office Deep cycle batteries. They do not honour their guarantee, only excuses that the batteries were damaged, yet one battery was new, where they wouldn't refund within a day of purchase, the other battery was tested by them at the time to be good. This has been an ongoing problem for 5 month's as neither battery worked properly from the onset, only giving 2 hours use, going down to 30 mins