You can always ask BT, on BT support lines, but if you do get a line reset you will most likely find that DLM will put it straight back after a while, I have the same problem, gaming on a BT connection is a bit hit and miss now, ever since they gave it unlimited on torrents and such, also giving away BT sports with a fiber connection, they have more to share now TBH.
I am in the same boat but my latency/ping is mapped with ThinkBroadband:
European servers are a no go area for me, so my BF4 gaming is limited to UK servers only, BT have said unless my ping goes over 100ms there is nothing they will do.
So on that note, good luck.
(On a side note, when I post to threads they die and get left on the shelf, the truth then gets hidden)