DSL All-in-L download speed dropped to 3mbps

Hi O2 Support

I've subscribed to All-in-L package for 2 years now and since last Thursday 9/March/2017, the download speed dropped below 3mbps.  Refer attachment for the speed test result.

I tried calling helpline 089-787 979 400 but no one ever answer the call.

PLEASE help urgently as I need a good connection when working from home.

What should I do next?

Regards

Llewyn