Same Problem here. I am paying for 20Mbps connection but the real internet speed (when accessing international websites like Youtube etc) is 4-5Mbps.
I have been asking for support to fix it or At least Vodafone should charge me for 5Mbps package only instead of 20Mbps.
It seems like their Technical Staff is clueless and struggling to find the very obvious problem or maybe they are trying to hide the problem.
But i am extremely disappointed not by poor service, but due to "dis-honesty" of the Vodafone towards its customer.