Capital One Continues interest charges on 1 cash advance Nationwide

I made 1(ONE) cash advance of $40 in February of 2017, Capital One charges a $10 cash advance fee, plus the same APR they charge for purchases.  What I didn't realize is that they charge that Cash Advance Interest every month unless you pay off the card in FULL.  I've been getting charge $1 since March for a $40 cash advance I made in February.  Now, I contacted their customer service number to get an explanation, and ask if I can pay the $40 cash advance and the interest on it, so I don't keep getting charge $1 every month and the said they couldn't separate Cash Advances from purchases.  I think this is a scam to rip off consumers, what's worst is that Capital One is problably not the only Credit Card company who does this.  Beware of the terms and conditions in your credit card cash advances.  Shame on Capital One for this, I've already pay $20 for a one time cash advance.