Disgruntled customer

I would like to express my disappointment in a service provider I have been with for the past 14 years. On the 27 November 2025 I was contacted by a consultant informing me that my contracts would be migrated to a lower package I was pleasantly surprised and agreeded to the decrease in my premium. I ended the call feeing pleasantly surprised. However on the 16/12/2025 whilst perusing my December bill I was horrified to find that my debit would now be R3649.51 as opposed to the supposed R1900 . I contacted customer care on the 19/12/2025 and till date MTN has not been forthcoming in their communique with me I am very disappointed and if I had the opportunity I would cancel my contacts earlier than usual I have six contracts in total and have never once been affected in this manner