Had the same sort of problem with the cable company. My credit card number changed when the card was upgraded, and I went online to add the new card. Apparently the change didn't "take" so the card was rejected. For 2 months. They finally called me about it to tell me service would be cut off if the account wasn't paid - and there was a sizeable penalty for the "missed" payment.
I told them I had been a customer for over 20 years and never missed a payment, and that I had used their online portal to change the credit card number, and they had not either called or emailed me to let me know of the problem whenit first occurred. They said they texted me - and I told them I had not told them texting was an option and with all the "spam" texts they send out on a regular basis I simply deep-six any texts coming from them. They removed the penalty without my even having to suggest it, and made sure the card number change went through.
For what I pay for my cable, internet and cell service they definitely owed me that much.