What started as an absolutely brilliant experience with the sales process, has now turned into a nightmare

What started as an absolutely brilliant experience with the sales process, has now turned into a nightmare. My parcel was arranged to be delivered on 14/6. I sat waiting for 4 hours like an idiot - eventually phoned the courier company and was told they couldn't deliver and the new delivery date is now 19/6. Lots of issues with this as I need the WiFi. I contacted Rain on 14/6 and the consultant promised it will be escalated. The courier company phoned this morning (15/6) and arranged for delivery on 19/6. Someone else phoned a couple of minutes later and said they can only deliver on 21/6. I paid pro-rata for the rest of the month on 9/6 for something I don't even have and won't have until 21/6! I chose Rain as the offer looked amazing and they could give me access to WiFi that I urgently need. Now I have to wait until 21/6. I offered to get my own courier company to pick up the parcel (because there are efficient courier companies who actually deliver), but I can't do that either because the courier company Rain uses must verify me. Surely other courier companies also do this??? Fully understand that I'm in a regional area, but why make promises and arrangements then that you can't keep? Or Rain should consider using a courier company who actually services outlying areas. I again spoke to Rain on 15/6 and asked that this matter gets escalated, but even if it does I still won't have the WiFi I paid for and urgently need until the courier company one day decides to deliver it. It's not just an inconvenience, I need the WiFi!