Slow down since contract renewal

[#1]

I have recentrly renewed my contract with Plusnet for Ulimited Fibre Extra, however since the renewal my connection keeps dropping and my speed is down to <20Mb whereas previously it was around the 50Mb mark.  I cannot contact on live chat and my twitter message has gone unanswered, how can I get this resolved?

[#2]

@fugrat 

If you suspect that this is some sort of conspiracy just consider the statistics. Assuming that the average contract length is 18 months, statistically one in 18 of all new random faults will appear within 1 month of a contract renewal or change of ISP.

Have you done the tests listed in this post?  https://community.plus.net/t5/Fibre-Broadband/Unlimited-Fibre-Extra-not-at-current-line-speed/m-p/17...

[#3]

Hi.  I'm not saying this is a conspiracy at all, I just want to know how I can get my fault investigated.  Nothing has changed at all with anything apart from my contract renewal.