MTN Contracts for Data not acceptable

My contract expired and went to an MTN shop who could not provide me with a reasonable solution so I chose a Month-to-Month package. When I got home I found they have put me on a 24-month contract. Since then I have been communicating with various people from MTN. eventually someone called and said he will give me a 40gb anytime contract instead. But i had to pay a Service fee of R374(excl) and discovered that the data is MTN Choice of 40gb - USELESS as i am a pensioner and sleep at night, so I dont need night time data. So my original contract of 50gb anytime reduced to 20gb daytime for the same amount of subscription. This is unfair.