Extremely Disappointed - I dont need a new number

On the 8th of Feb I asked to be contacted regarding an MTN Data contract for 2gb per month for R99. I was under the impression from the beginning that I could use my existing Pre-paid number for the contract. When the consultant called me to finalise the details of the contract I was asked to agree to a new number at which point i said to the consultant that i dont want a new number, to which she responded that this can be amended once I receive the sim card. This is incorrect as I have contacted MTN customer care for assistance who seemed to know nothing, i then contacted MTN Complaints who were unable to assist me either, so i have now forwarded to the cancellations department because i have absolutely no use for yet ANOTHER number, only to be told i will be charged an early termination fee. I want to cry. MTN has wasted so much of my money now. I feel like i was taken advantage of by a salesperson in the whole process and now it is costing me dearly.