Onecart - half of my order received

Placed an order via the one cart app - all items ordered from one store. Half the item arrived but only discovered after the driver had left. No explanation no apology. Contacted Sophos via WhatsApp she simply said ‘they will refund you’ not sure who they is. Then she started deleting her messages which os’s a bit dubious. Think twice before relying on this app as I am now out of pocket to the tune of hundreds of rands still with no idea how to process my refund.