incorrect package

I am yet again having to complain about how hopeless mweb is. For years now I have been billed for a 200 gig package with 200 gig night time, suddenly I get a mail today from mweb about my mweb sale agreement which states a 150 gig package. so I call mweb and for some unknown reason mweb now have me on a 150 gig package. If this is the case then refund me the monthly difference which you have billed me for all the years I have been with you. you agent was most unhelpfull insisting I am on a 150 and then to be told the agent who I had asked to upgrade my speed to 10 meg line took it upon themselves to downgrade my package without my knowledge. your agents don't have a clue about customer service. I had to call in again and hold for absolute ages to attempt to fix the problem. cancelling the request to upgrade to a 10 meg speed and re instate my 200 gig package and re apply for only the 10 meg speed. what a waste of my time. can someone who knows sort this out.