EXPATS BEWARE OF VODAFONE IN GERMANY

I recently moved to Germany and not being fami**** with the data rates and charges I decided to use a "trusted" and well known company. I made the biggest mistake as I got a contract that costs me €24 for only 5GB of data. I only later saw that they sell 30GB for €19 to prepaid customers? After numerous calls trying to find an english speaking agent, they still refuse to give me a better deal or more data for the large amount I am paying. I then resorted to asking if i can buy out my contract in full so that I may end it and they also said this is not possible. It literally feels like i am being held hostage. There is ALWAYS some extra charges on the bill that takes it above €40 every month, and this is all for just 5GB. I just want to get out of this contract as I have clearly been taken for a fool! Shame on you vodafone for pretending to be a trusted household name and the ******ing expats like this. The least you could have done is let me buy out my contract that I signed so that I can get rid of you.