Unfair practices

I have no idea who else to contact. I have had a Shell Citibank card for going on 10 years. Payments were always on time and the balance was well below the limit. I am an 88yr old woman with one authorized card on this account for my grandson. We had a payment due in October that fell on a Sunday, the payment posted on a Monday. 30 days later our interest rate jumped to 29.99% making my minimum payment $135.00
The card is now maxed out as I am on a fixed income and my grandson was laid off, we made the minimum payments but had no way to make any headway on this card. I hold two other cards with 12% rates and are in good standing. We called Citi for help and were told there was no help available. I also have a Sears card (now managed by Citi) with a zero balance which was my back up emergency card should I have to make large purchase for an appliance, water heater etc. Shortly after my call to Citi I got a letter in the mail they they were closing my Sears account because of "delinquencies" on other Citi accounts. I have an auto loan and an equity line and two cards, I have never been late on a payment so I am not sure what delinquencies they are talking about. I called CitiBank again and asked them for help with the interest rate or if we could close the account to and enter into a quick pay off agreement. The customer service person told me no, there was no "hardship programs" available at this time. The only way to do that would be to default on the card and then collections would take over. I asked her again to repeat that and from what I understood Citi was not willing to help a member makes equitable payments to fulfill my agreement and get this card paid off unless I defaulted. She said "yes, that is the only way to get a payoff agreement".

It was then I decided no more payments to Citibank, I allowed the payment to lapse. Starting on march 17th I received no less than five calls a day at my house from Citibank starting as early as 7:55 am and this includes Sundays. I documented every call and the time which netted over 70 calls in a 3 week period. After a few weeks the calls finally stopped and I got a letter in the mail stating I was behind and to call CitiBank to work this out. I called Citibank on 5/10 at 6:00 pm CST and was told the letter I got was not a collections letter and they could not help me until I was in collections. The letter stated Citi was about to report me to the credit reporting agencies. The representative on the phone called the "settlement department" who refused to help or speak with me until my account was in collections. The balance of my card was $3990.00 In March, It now has over $350.00 of interest and penalties. I offered to pay $400.00 per month as a direct draft from my checking account to get this done and over with. They again refused, I cannot pay this card off with this interest rate. Citibank is a predatory bank and at age 88 I could care less about my credit or how they think they can effect it. I feel if a customer calls a bank and makes a good faith effort to make reasonable payments the bank should help the customer instead of doing more harm. This balance will remain unpaid until CitiBank extends to me a bit of help. I am in no way disputing the balance on my card, I am filing a complaint regarding their business practices as a whole.