Unhappy

I ordered two devices from Rentoza one was delivered which was a Samsung without any issues, I was meant to get an iPhone delivered around the 23rd of February but received an email last night to say there is a back log with the iPhone and they do not have the iPhone 12 127GB available but I have the option to take the iPhone 13 but that would mean the subscription will be more which I was not happy about, I than opted for the iPhone 11 but later found it is 64GB and advised that I am unhappy with 64GB memory space ,than requsted that they cancel the order and process my refund. I was told their cancellation team will be in contact which never happened ,I than git an email about shipment which I s=email them about and than got a refund email which said was for the Samsung I got delivered .All I need right now is for them to cancel the cancellation, cancel the refund and send the device and refund me of whatever amount will be the balance from what I paid. I have since been sending them emails but am not getting any reply I truly am disappointed about the level of service I have received from rentoza