Sorry to see you are having major problems with your TIVO box. You are right, you'll need a new box as the hard drive has failed.
Have you tried signing into Service status at the top of this page and run a test against the TV box? By doing this VM should be able to send a signal to your box and try to repair it. The automated system may determine it needs to send out either a replacement box or book an engineer appointment.
Sorry to say if that doesn't work then you need to contact the Faults team again. 150 from a Virgin landline, or 0345 454 1111, options 1,1 and 2 (Faults) butbest to call at 8am to avoid call queues
You could also try the text messaging service. Just send a text with a description of TV Faults to 07533 051809. Your message will go into a queue and a representative will respond to you as soon as possible.It may take a few days.
The Service you do for others is the rent you pay for your room here on Earth - Muhammad Ali