Sure it's required and they should have to comply, but this is a secured LoC, so there's no interest to gather in the first place. Unless I'm grossly misunderstanding this? That's a stupid high APR, but you should effectively have a bill of $0.
The collateral is only returned to you when you close your account or upgrade it to a non-secured card. You don't use the collateral for the monthly bills, just like if you rent an apartment you don't use the security deposit to pay the monthly rent.
Very impressive.
1. You give a business some of your money.
2. Business gives you some of it back.
3. Business charges you insanely high interest on the amount they gave you back, until you return your money back to them.
4. Profit. So much profit.
The only reason someone would apply for one is to build credit, and missing the grace period while subjecting oneself to high APR is pretty much the worst thing one can do at that point. It's worse than not getting the card at all.