Product: Mortgage

About XXXX, I opened a Home Equity Line of Credit with XXXX XXXX XXXX XXXX XXXX based in XXXX, Fl. The XXXX XXXX XXXX was subsequently taken over by the XXXX, in either XX/XX/XXXX or XX/XX/XXXX, and the loan was sold at least twice. The line of credit amount was $ XXXX and the initial draw was around $ XXXX. This amount was paid off and the account was dormant for some period of time. At some point, the loan was sold to Sovereign Bank and they forwarded checks to me in order to access the line as well as a solicitation letter stating that the checks would expire XXXX XXXX, XXXX. I did not use these checks. I subsequently received correspondence and checks from Sovereign/Santander Bank and again, did not use the checks. I have a statement from XXXX/XXXX/XXXX reflecting a XXXX balance. Around XX/XX/XXXX, I needed to have my roof replaced and contacted Santander Bank to determine if the line was still open. I was assured it was and so I accessed the line for about $ XXXX was paid off and in XX/XX/XXXX I accessed the line again for some remodeling. I believe that since that point, the account has had a balance with I believe the highest balance at around $ XXXX. The current balance is about $ XXXX. The monthly payment I make is well over the minimum interest only required as I usually pay {$500.00} and sometimes {$1000.00}. 
This brings me to the current situation which is both shocking and unbelievable. On XXXX XXXX, XXXX, I received a letter from Santander stating the following : " During a recent review of your account, we discovered that your Home Equity Line of Credit Agreement called for a balloon payment that was due on XXXX/XXXX/XXXX. Due to an oversight on our part, we continued to accept payments made after the Agreement matured on XXXX/XXXX/XXXX. Because of your willingness to make payments on this line of credit and our commitment to customer service, we are extending the date that you have to pay off this line for an additional 120 days from the date of this letter. '' I immediately contacted Santander believing that this must be an error. I was given the run around but the bottom line was that there was nothing that could be done and the tone was almost as if it was my fault? 
My points : 1. ) They could not advise when they purchased the loan and obviously did not review the documents prior to loading on their system. 
2. ) I asked to see a copy of the note as after all these years I do not have this document 3. ) Even if this balloon payment clause is correct, they not only allowed, but encouraged me to use the line I contacted Santander and I said I would be open to paying off the balance but could not accomplish this by XXXX/XXXX/XXXX and requested an extension for about XXXX months assuming I pay {$500.00} a month. They would not agree to this and advised if not paid by XXXX/XXXX/XXXX, the account would be considered delinquent and would affect my credit I have worked my entire career in lending with large companies and most recently worked for XXXX for over XXXX years. I have often read and heard about situations that people have encountered related to banking errors or oversight but have never personally encountered any issues. My credit is excellent and my bills are always paid on time. 
I appreciate your time and look forward to hearing from you in the near future.