I can't pay my bill!

We have tried every payment method you offer. We tried 6 different business and personal credit cards and all are rejected by your system. I paid after this rejection 1500.00 at the Home Depot and had no issues. So I sent an employee to your local office and you wouldn't accept cash. I'm not sure why this bill is 1200.00 when I thought we locked in the 109.00 per month promo but it is what it is. How do I resolve this? Your office refused cash from my accounts man! Said he wasn't authorized. OK I authorize Brent Simmersville to be my representative on my comcast business account. Or do I have to do this in person