I'm sorry for the difficulty you've had in reaching us, but I'll be happy to help with some of your billing concerns. Our pricing updates automatically based on the highest number of contacts in your account during that billing cycle. To go down to a lower plan, you simply need to remove contacts from your account. Your next bill will stay the same, based on the highest number of contacts in your account during that cycle, but the bill after that will be reduced automatically to match your new contact count.
Anyone in billing or general support should have been able to assist with that, you can reach one of our agents at any of the numbers listed here.