MTN taking money ********ly

They are *****ing money from you. End of august my husbands account was debited with R164 more than his top up account monthly, when asking they told us that they attempted to contact him regarding insurance but also admit they were unsuccessful, yet they deduct money for insurance for a phone which is not even the phone with IEM number he received from MTN as that phone was taken at gun point a year ago already, now asking them to cancel this they asking him to go to a MTN shop to fill in a form to cancel this, something he did not want or agreed to, how the hell is this possible? according to them, he must prove he never requested the insurance, which they admitted to contact him unsuccessfully, how can this be his problem? This is theft. His contract was due for upgrade now the 24th, but this will probably not be happening as this is very bad service.