Failed to deliver as promised

I bought a cellphone from a service provider that uses ram for their deliveries. I then received an e-mail at 08:07 in the morning saying my parcel will be delivered be between08:00 - 17:00. I called their office around 10:00 asking them about the delivery of my parcel. The lady told me she doesn't have the numbers of the driver and doesn't know where the driver is and doesn't know what time my parcel will be delivered. She then asked for my alternative number to which I gave her. She said they will call me back. They never did and I haven't received my parcel. Since they are not working during weekends it means I can only make a follow up on Monday.