Can't change package as property coming up as not serviced

I've had Virgin here since I moved in in 2003.  It's flats and first there was just the building name on my account then changed to include flat name about 5 years ago.

I keep on top of my package and renegotiate/change as needed.  It's that time again and my bill is due to go from £57 to £170 on July 3rd so considering options. 

They have finally said that my address is coming up as not serviced. This is clearly not accurate as I currently have a service I am being billed for, I can only think their address database changed and they are not finding the flat

I've been trying to get this changed since June 2nd and so far  there's 2 chats and 4 phone calls with no one able to help.  Every time we call they say someone will get back in 3 days.  When they don't and I call they reset the clock so I'm always 3 days away.  2 possibly 3 complaints have also been raised

I'm at a loss of what to do next. I've been ill and  I can't afford the increase but can't seem to do anything to reduce my bills.

Is there anything else I can do to fix this?