Dominic,
There are two different types of RateExceededErrors. There is the more common rate limit exceeded error that results from too many requests per minute, which is the one that can be avoided by using MutateJobService. You are running into the less common type which is based on your access level. (
operational_limit_based_on_access_level)
The MutateJobService helps you get around request rate limiting, not operation request limiting. For clarification about the difference between request limits and operation limits see the "Difference between a request and an operations" heading on the same page as the above link.
A MutateJobService call is a single request, but is still limited by the number of mutate operations. See the chart on API operations on the
Rate Sheet. So you can get as many things as you want in a single call, but each API object you mutate counts as a separate operation, even if it is accomplished in a single request.
You are correct that you will need to upgrade your token to get more operations per day. It is still the same form because upgrading your account requires justification for such heavy use of the API. Make sure you explain why so many daily mutate operations are required in the form field for the question "Do you plan to make any mutate calls to the API, or create/manage campaigns via the API? *"
Hope this helps!