Check your Telmex bill

When I checked mine this month, there was an additional charge of $39 under special services.
The service was described as "seguro inbursa integral". A quick visit to Telmex revealed that this is a charge from an outside firm who are supposed to call and sell their services with the charges being added to your Telmex bill.
We did not receive any call, and the lady at Telmex said that it sometimes happens that a charge appears without approval.
A check with senor google shows that this has been happening sometimes for more than 6 years.