Adult Advertisements in On Demand

So. Tonight I was watching a movie when my six year old daughter came downstairs after having had a bad dream. I let her sit on the couch with me and watch the last two minutes of my movie and then proceeded to drop back into On Demand to select a children's movie for her to watch.

Needless to say I was both mortified and instantly furious when an advertisement for masturbating milfs came across On Demand, even though I have adult content disabled. I immediately called technical support and was told that there is no way to block porn advertisements in the On Demand section. Is this true? Online support told me the exact opposite, more than once, and even suggested resetting my box to ensure all changes take effect.

If so this is a serious oversight/limitation. One that truly makes me an unhappy customer.