Clearly, none of us reading this, know what you told the client to expect and what standard was achieved, in cleanlieness, or drying time.
However. If the suite was lightly,or moderately soiled and there was no reason, other than overwetting, for the extraordinarily long drying time, particularly when using such extreme measures, something has gone wrong, assuming you are not new to the business.
If you normally achieve better results, then you should start by checking your machine over, particularly the filters, it might be obvious to me, or most of the others on here, but this check is not obvious to untrained, or inexperienced operators.
A clogged air filter, results in reduced vacuum / airflow, which results in overwetting. Yes it should be obvious to anyone that the return tank has much less in it than you'd expect, but it happens !!
No matter what the cause , I can't imagine any association behaving in this way and don't believe they would..
Good luck
r m