you thought about this,really?
so you sold 300BTC at $11.. so that gives you $3300
buy them at the $13 price giving you around 250BTC. transfer them to another exchange such as bitcoincentral or btc-e and sell the 250 at the $13 and guess what...
you still have the $3300 you were happy to have several months ago... but in a different exchange that may accept your identity..
if you sold out several months ago you would have only had $3300 and you were happy with this amount. so you have not lost out anything but time. it would be worse if mtgox only returned 2cents to you or said you cannot have any money at all.
dont blame bitcoin for this.. blame the companies and the government laws that restrict your use of FIAT i would also recommend looking into the daily withdrawal limits stuff too.. as withdrawing too much in one go will flag extra identification being required by banks etc.
so withdraw 500 a day or whatever the limits are to ensure theres no red flags for high value money movements