No, no broker can claim your funds for their own, on account of being inactive. Let me put it this way, no trader is under any obligation to guarentee the broker spread commissions, for each month.
Or to put it in another way, they cannot claim your money for their own, for this is not a paid membership and the broker takes his cut from the spread. At most, they can freeze your funds for inactivity which should be removed once you send in a request.
That said, some brokerages do seize client funds for their own, I would suggest that you do a runner..and see if you can explore other options to reclaim your funds..