Hi gjc28,
Try rebooting the Tivo please. If the channels are still greyed out then you need to phone 0800 953 9500 to get your box activated/reactivated.
You will need the box serial number, and your account and area number
EDIT
You could also try speaking to sales in order to get your box and TV services reactivated. Please call either 150 from a VM landline, or 0345 454 1111 and choose option 1, 4 then 1. Or you can send a text to 0753 305 1809 but texting may take a few days
Dave
The Service you do for others is the rent you pay for your room here on Earth - Muhammad Ali