Only the owner of the Kickserv account has access to the Account & Billing settings. If you are the account owner, no problem! When you login to Kickserv, you'll be taken directly to the billing page to update your payment information.
If you are not the owner, you will need to contact the owner and have them update the payment information.
By default, the person who originally signed up with Kickserv is considered the owner of the account. Problems can arise when the original signup was not done by the owner of the company, but by someone who is no longer with the company. If this is the case for you, send an email to firstname.lastname@example.org or call 1-800-530-3156 and press 3. Leave your name, your company name, and the best phone number to reach you. We'll call you as soon as possible and assist you with updating your account.
You may want to take this opportunity to make sure that the actual owner of your company is designated as the Kickserv account owner. You can check this by going to Settings > Manage Users. In the list of users, the account owner will have "Account Owner" listed in the Roles column.