That's the thing with a margin account. You agreed to pay interest if they lent you money. If they refuse the withdrawal they are breaking your agreement. You probably told a little white lie when you said you were an experienced investor on your application, along with saying that you had read and understood the terms of use.
The problem isn't paying interest on money I borrow...it's paying interest on money I didn't. Them saying that the funds haven't settled therefore it is actually being taken out on margin is a total racket. Learn to read a post before you try to flex that you can read a contract. The agreement means nothing if not equitable. In fact some brokers are switching to one day settlements now...next will be zero days because people like me don't just accept the status quo. Case in point. I have my current broker allowing me to trade previously restricted options by setting up my own margin requirements. I told them what I wanted and they gave it to me.
Well I wish you luck in getting your interest back. Who knows you just might as the brokerages like to keep high rollers happy.
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It works out to only $12 or something for the weekend so not really bothered about it ..was just the principle. Anyway, I didn't have much in the account at the time. I just wanted to trade those particular instruments or would have to go elsewhere. Selling puts is a defined risk trade. Their own margin rules were what were leaving them exposed to risk imo. Every little bit counts. They don't want to lose a customer.