Worse service over debit dispute

So disappointed in mtn, having a contract for more than 10 years. Took a second one out in May... Mifi contract which was most needed. My existing contract had a limit of 8000 (which allow me to activate when needed.) New contract they gave me a limit of 2950 (which was activated without my knowledge. Second debit was R2985... To my surprise ☹️I query and was told via email and contacted the customer service and was told that it was my out of data limit that activated. I log a dispute with complaints at mtn. I only received an automated reference and nobody contacted me, untill today. After 14 days I had to escalate to another department. Mtn block my phone in the mean time and I continue to make my monthly installment as per contract, unfortunately I don't have the extra income, that why I submitted a complaint/dispute on debit ... I am lost for words with the service I received.