Use the 'Check Service Status' facility (top right of this page) to see if there's a known issue affecting your area. If not and you have access to another phone, contact VM on 0345 454 1111 and report the fault.
I have checked your line and it's showing blocked so before I arrange for a technician visit can I just confirm whether you have tried another handset in your Virgin Media socket just to eliminate any equipment fault?
I'm assuming calling in to your line is giving you an engaged tone?
Your line shows blocked from here so this could be down to your handset, I just need to know whether you have tried removing everything from the Virgin Media sockets and trying a different handset if you have one spare?