The order executions in Oanda is insane, I think it's...

The order executions in Oanda is insane, I think it's one of the best brokers I have ever tried (in terms of executions). I use MT4 and I have been very satisfied. Even better, they have no swap fees, but Oanda does charge interest by the second. Spreads is good, but sometimes it can jump from 1.9-pips for GBPUSD to over 30.0-pips (as far as I know, I haven't checked other pairs). Oanda accepted a deposit from my bank but wont to allow me to withdraw funds. I don't understand why they can't let me withdraw if they can accept my deposit from the same bank?