Movistar keep charging me after end of contract (baja)

I was a Movistar customer with both home fiber and a cell phone line prior to December 2021. On the 15th or 16th of December I called and asked for a "baja" to end my contract. I was promised by the customer service agent on the line that this would be done within a few days .

Beginning of January I received an unexpected bill from Movistar for the period from mid November until 17th December. I called customer service again to verify that my account had, in fact, been closed as I was promised by Movistar customer service agents.

When I called, an agent told me that my contract with Movistar was still active and that they would keep charging me until it got fixed. I had to call 5 times during the month of January, repeating my story to each individual customer service agent every single time. No notes appeared to be kept on this error. On 26th January I received an email to confirm that my contract had ended.

Movistar continued to send fraudulent bills to my address from mid December until 26th January, because despite their promise to close the account, and the return of all Movistar networking hardware to their store, this account was kept active.

Clearly there is a competence deficit within Movistar, or some decision makers have decided to continue issuing charges for a service that had been fully canceled. I spoke with my bank and they issued a chargeback for the fraudulent billing.

I began to receive letters from movistar threatening to discontinue service (which I had already canceled and had been confirmed canceled).

Following those threats, the next letter contained a threat to sue me for some 45 euros. This harassment is unacceptable. I have fulfilled all of my obligations to cancel service and refuse to be extorted by these criminal means.

Movistar will quickly find themselves on the worst end of a lawsuit if this is not resolved immediately.