Suddenly not able to make payment arrangement

Every month I have to make a scheduled payment for after the due date, because of when I get paid. I get paid on the last business day of the month and also on the 4th of the month. My payments are generally made between these dates unless the last business day falls before the due date. You can see when I pay in my account, it is almost always between these dates. I also enrolled in the installment plan a bit ago to pay down my past due balance. Suddenly,  this month I am unable to make my payment on July 1st instead of June 28th. I am being told service will be suspended on June 28th. Why am I Suddenly not able to pay my bill as I generally do? Also, I had an agent tell me to call back after suspension and more options would be available to me. I asked for details and received none. I also pointed out that waiting until after suspension is counter intuitive to working with me to pay the back balance as other fees will then be accrued. Then the agent said to call back tomorrow, which is the 27th for more options. Why would there magically be more options to pay one day later? I took screen shots of this conversation as it just didn't seem like i was receiving correct information.

I'm very frustrated as I have been a customer for many years and always pay my bill. I have been fighting with a past due balance, but that's why I signed up for the installment plan. Comcast's automated system seems to rule everything and for some reason the system has decreed that I cannot pay the bill on July 1st this month as I do any other month. Surely, there is a fix here somewhere for a long time customer to make a payment three days later. As I said I get paid on the last business day, but the payment must be scheduled for the following day as funds are not available at midnight when most automated systems pull payments. I am just asking for a reasonable solution here.