Companies or Websites for automatic billing & ticketing service?

Hello

Please anyone can suggest a good company that offers both automatic billing & ticketing service?

I am offering web related services to my clients & want to charge them automatic recurring payments & give them logins to support/ticket system so that they can submit their requests/tickets any time they want.

If they stop paying then their support system logins should not work and vice versa....

Can anyone please recommend a good company/website that offers both of the things?

Many Thanks