Terrible service on guarantee delivery

We placed an order on takealot that does their delivery through Mr Delivery and we paid extra for guaranteed delivery for the next day. I started phoning by 11 already wanting to make sure when they will deliver as the address is my work address. After promise after promise and 6 calls later we are still waiting with nobody getting back to us. Sitting at work for an hour after I knock off and still nothing. What kind of service is this?!?! Why pay extra for something and its not being attended to as promised?! Worst service ever!! Then getting told thry will deliver at 8!! After how many times explaining its a work address and I finished at 4:30 and the branch literally being 1 km away??,???