a few things you have to consider:
-the file youre downloading has a very bad seeder/leecher ratio. remember, kung kaunti lang ang sources ng file na dina-download mo, mababa talaga makukuha mo. i expererience that sometimes. pero kung kelangan ko talaga yung file, edi tyaga lang.
-pldt's lines are congested. kumag kasi mga ISPs ngayon para madami lang customers kahit pumapalya na servers sige parin.
-you have a faulty component. it could be a grounded wire, burned out router, who knows?