Pathetic customer service! Wont support again

I am appalled by the service received by dell. I logged service related issues with the technician on 4 May 2020. As much as I understand that Covid has been a problem for companies, it is now 16 November and my laptop has still not been fixed. I am constantly promised that it will be sorted and then nobody shows up to fix the laptop as an appointment has been made. I am still waiting for parts to arrive and then get told that the company has received them and the process can continue but then nobody shows up again because “the parts haven’t arrived yet” I wad offered a new laptop because of the inconvenience (which I opted into)but that then came with its own mountain of issues aswell as then I got told that I cant have it because I cannot provide the original invoice of the machine to show where it was purchased from. As the consumer, I only have my invoice from the shop where I purchased it from which I provided and the onus shouldn't be on me to find the very first invoice relating to the machine. I purchased this machine new and sealed and still this is not enough for dell. This is such pathetic service.