Apple would do a big favor to developers by being a bit more open and transparent with the regulations.In your case this will probably be the relevant guideline that they may cite.
> 11.9 Apps containing "rental" content or services that expire after a limited time will be rejected
It seems that Apple's review team has interpreted SaaS to fall under this guideline.
> 11.9 Apps containing "rental" content or services that expire after a limited time will be rejected
It seems that Apple's review team has interpreted SaaS to fall under this guideline.