Product reviews not always accurate

Be careful to buy batteries or electronics etc from Bob Shop based on the reviews. Bob Shop limits product reviews to max 3 months which means that any product defect that occurs after 3 months cant be posted on their site so its unlikely the product will have a fair review on its quality and how long the product will last. I bought 8 Royal deep cycle batteries from Net Deals on Bob Shop claiming on their page they are ideal for load shedding. 4 of the 8 became defective after about 4-5 months and they rejected a swap, claiming the batteries arent suited for load shedding however Bob Shop would not allow me to write a product review because it was longer than 3 months since purchase.