PHD - selling bad quality products

Bought batteries for my inverter in Jan 2019 which costs R1767 per battery which should have lasted for 4 to 5 years, instead of GEL batteries PHD supp**** me with an inferior import which only lasted 18 months (not a gel battery), not disclosed to me. PHD are not willing to assist and offered me R200 per battery if i buy new batteries from them. PHD has sold me inferior products and refuse to change them. PHD MD Warren stop taking my calls today. The representative from PHD told me that various customers are having various issues.