Hi Eamon66
Sorry to see the position that VirginMedia Ireland have placed your mother in. We can't do much to help here as these forums are for Virgin UK which is a separate company using different unlinked systems.
There is a live messenger chat you could use with VM Ireland (along with other contact methods) on the following page. https://www.virginmedia.ie/contact/
I've had a quick look through their help pages but found very, very little in regards support
/virginmedia.ie/customer-support/support-by-products/home-phone
Will your monitored house alarm still work?
Please contact your alarm provider for further details.