IIRC, there was a hold period of 5 or 7 days [not sure which one exactly and I could be wrong] for such things so I'd suggest trying it again in two to four days.
The holding period is just three days and according to their
support page if you buy cryptos with a credit card your purchase might be subject to this holding period.
Not sure if this is the case, though. Because the holding period shouldn't affect the ability to trade bought coins, exchange them back to cash or make new deposits. It only restricts the buyer from withdrawing out of the exchange.