That's no problem at all dcheung87.
If the phoneline is connected to the master socket or extension, there could be a crossed line or something loose which we can send a tech to investigate. It could also be a home phone switch over to the newer IP systems, where the home phone uses the internet to make/receive calls rather than the older cooper lines.
If you are able to pass account security we can discuss the account as a 3rd party - I can run fault checks if needed without this, but I would not be able to discuss the account.
If you'd like for me to take a look, please join me on private message so I can locate your account and pass account security. You can see your private messages at the top of the page, in the envelope icon. If you'd rather wait after you have tried a new phone, we can also just wait for your update.