Complex formula to predict credit card statement and payment amounts

The attached sheet is part of a cashflow projection I use personally and in my business. The object is to have a flexible tool to predict the statement and payment amounts for a credit card. Recurring charges are listed on the left and show up in the correct weeks of the year, based on a day-of-month value. Statement and payment amounts are also calculated on a given day-of-month basis, allowing me to re-use the sheet for various credit cards.

In practice, when I get the actual statement, I overwrite the formula in the appropriate cell with the actual statement balance. I think this is throwing off the balance over time, causing extra-large and even negative statement balances. 

I'd appreciate any help that can be offered to make this work as intended.