So a few days ago my line rate suddenly dropped from ~14000/1000Kbps to ~5000/400Kbps.

After doing a isolation test it turns out it was the jack point. Their are 3 jack points in the house in total, the faulty one, one that doesn't work at all and a third that is fine. 

I am renting and just wondering if the landlord has any responsibility to fix the faulty jack points as the only one that works now is in a really inconvenient location.

Otherwise what is the best way to get this fixed myself?