Wrong and damaged items deliveries, client carries additional costs

Fed up with Takealot, received a damaged cat water fountain (return ref MRRN-85WQE-DZE5), returns and credits take forever so purchased another whilst waiting for credit since have sick cat with kidney disease that needs to be encouraged to drink more. 2nd fountain Delivered yesterday now minus a cleaning part. Ordered filters upfront with first fountain, now that I actually have a fountain opened filters and they've delivered wrong shape ((square rather than circle advertised and purchased) return ref MRRN-ZM7BZ-WZB8. Then according to Takealot they cannot replace item since supplier out of stock but they still advertising and selling he correct item. They rather want to credit my account so I now lose out on preferential price I secured when originally ordering and must re-order at higher price Takealot should replace item and carry the cost for their ongoing VERY POOR SERVICE and inconvenience they cause customers, rather than client carrying additional costs.