Weird Continuous Ringtone and Internet Disconnects

Question

We had a new phone line activated towards the end of February.  An engineer visited our local exchange for set up and everything was tested working perfectly.
We then ordered broadband with O2.  When the broadband was activated (early March) our phone no longer had a dial tone and we could no longer receive or make calls….Strangely though the Internet worked perfectly.
We reported the issue to BT who ran a line check and identified a problem with the exchange box.
An engineer was arranged to visit our local exchanged within a couple of days and fix the problem.  24 hours after reporting the fault the phone line started working again prior to the engineering visiting the exchange.  We called BT to clear the issue and cancel the engineer visit.
We have noticed since the phone line has started working again, we now have a continuous ring tone and at the same time the internet drops out then reconnects.
So far we have done the following to identify the problem with our equipment.
Tried 3 different phones (on their own with no filter our router connected) in the test socket and we still get a continuous ring tone.  Used 2 routers (O2’s and our own netgear) along with 3 different ADSL filters and the internet will still drop out when we receive a call.
I am convinced there is still an issue with the exchange as it was never properly investigated when we first reported the issue.
We have spoken to the foreign call centre that run the line checks, unfortunately as we were cut off during the call we had to call back and therefore were dealing with two support agents at the same time. One of the support agents ran a line check when the landline was in use so it has reported a fault with our equipment which according to the first agent, it did not.
The problem is getting a bit tiresome now and we just want a working phone line without these niggles.  The foreign call centre seems only capable of running a line check and our particular problem seems quite unique.  Has anyone else has this issue or is there a direct number for a UK based support team who can help deal with the complexity of our case?
Thank you for reading.

Answer 1

This is simply a customer to customer support forum, I have no involvement with BT or Openreach any more, having retired a couple of years ago.
My diagram shows the points that would normally be checked for dial-tone, its actually quite simple for the Openreach technician to identify where the problem is, by simply using a portable phone.
If it proves to be a lack of dial-tone from the BT Exchange equipment, then the Openreach technician can move your line to another piece of equipment, then leave it for BT Wholesale to sort out.
If the dial-tone is missing after it comes out of O2s broadband equipment, then its possible for Openreach, with the assistance of O2, to move both ends to a different piece of O2 equipment.
If the fault is past that point, then Openreach are still responsible, right up to the master socket in your house.
As you can see, BT retail are only concerned with the exchange equipment. Their line test system will test from that point onwards. So if there is a disconnection in the exchange, it will indicate it during the line test.
Anything after that point, has to be dealt with by Openreach, who can be called by your ISP or BT.
As the problem occurred after you had the broadband installed, it would tend to indicate a disconnection in that area.
It could be something simple, like a broken wire, or unsoldered connection.
I am sure it will be resolved.
There are some useful help pages here, for BT Broadband customers only, on my personal website.
BT Broadband customers - help with broadband, WiFi, networking, e-mail and phones.