The Alliance of Independent Authors is an excellent resource for self-publishing advice. I frequently recommend that anyone purchasing self-publishing services check the Watch Dog page of ALLi - and their list of Best Self-Publishing Services.
There a second reason for checking that Best Services list - it tells you up front if they are a member of ALLi, which might make you leery at first, but members have to agree to a code of standards. This includes responding to customer complaints appropriately. So if you do use the services of a member of ALLi, you have the strength of that commitment to support you if there's a problem.
Worst case scenario, you could let them know you'll be telling ALLi if they don't live up to the standards of the organization.
I need to renew my membership and get on that list!
