Suspicious activity/MTN agent

Yesterday (13-07-2023) I received a text from MTN stating that I ahve been successfully authenticated. This was rather strange, followed up with a call from an MTN representative stating that my DATA contract is due for an upgrade. I confirmed this to be accurate and stated that I haven't looked into options regarding an upgrade. When I queried about the SMS message received, I was told that someone phoned on my behalf, imposing me, but failed the security questions. He even gave me the cell number (not known/linked to me) which he phoned in from. When I asked more info on it, the rep said I needed to contact the call center or visit a branch. This was rather strange, firstly trying to do an upgrade and then informing me of someone trying to breach security.

I visited a branch yesterday and was informed that an upgrade was initiated without my consent. From what he could gather and information available to him, he could not see any other suspicious behavior on my account. The agent did mention it could be a possible "sales tactic" from the call center agent.

Could this please be investigated.