Perfectly Healthy SA review for Propel Upsell & Cross‑sell

The app has massive loop holes in it, it allows a customer to delete products in their basket but the discounted upsell price remains, meaning the customer then only buys the discount product alone. It also allows the customer to multiply the discounted product's quantity and buy at the discount price as much as they want without adding more of the original upsell product? I already informed them of this months ago but still no fix.