My O2 DSL keep disconnecting often! need help to rectify this issue

Hello O2 team,

I live in XXXXXXXXXX. i have O2 DSL S plan and the internet is keep on disconnecting frequently. i have tried all the possible options like resetting the modem, restarting the modem etc. still the problem persists.
As i am a techie myself, i believe the problem is in building wiring or may be in O2 side.
I need immediate help in rectifying this issue.

This issue is been persisting for past 4 months. and i am unable to use the internet properly and i am paying for the contract uselessly.
kindly help

Edit o2_Lars: Since this is a public forum please never post any personal information like phone numbers, adresses, customer numbers, and so on...