what credit card offers best interest free days per month

SuperHan

This sounds more like you have an underlying budgeting problem.

I would recommend looking at a statement of affairs, or having a few low spend months and trying to stop spending on credit and switch back to be able to spend with debit card. You could be in real trouble if there is an unexpected dip in your income as it sounds as though you are constantly spending next month's pay this month.

But back to the original question, try ringing MBNA and seeing what they can do. For reference, my MBNA card statements on 23rd and requires payment by 10th, so I get about 47 days.