Hey @pawat12 and welcome to the Virgin Media community.
I'm sorry to hear that you have an issue with intermittent dial tone on your landline.
How long has this issue been going on? Is the problem at certain times in the day or can the dial tone be intermittent at any time of the day?
I have looked into your account and can see no issues on your account but clearly there is an issue. Are you able to try with a different handset in your hub?
Have you reset your hub since the issues started?
Regards
Steven_L