MTN Giving out confidential and personal information to tele marketers.

MTN are a totally ********* and ********** company that care nothing about their customers confidentiality . They gave another entity - Summer Sun Trading- all my personal details regarding my 3 packages that I have on contract with them. They also gave them all my contact details and e mail address. This was done WITHOUT my permission !! A representative form Summer Sun Trading contacted me on the 10th March 2020 , and impersonated himself as a representative of MTN. He did not tell me he was from another company. I believed him as I was under the impression he was from MTN as he had every single detail of my 3 contracts. He then proceeded to explain options on my upgrades. I told him to e mail the details so that I may look at them at my leisure. I expressly instructed him NOT to change anything until I had given him permission. He just went ahead and changed all 3 of my contracts - without my giving him the go ahead !! On reporting this - in person - to MTN main branch in Richards Bay on the 14th March 2020 , I received the pathetic and uncaring service !! They said it was my problem and not theirs. I have to sort it out. They want nothing to do with my problem !! If anybody out there has had a similar experience , please tell me what course to take. Thank you.