I presume they are the type with a chrome cover that comes off with the barrel and the bolt head is underneath? The keys are all different,but i have got them off using a similar style key and shaking it up and down in the lock and rotating it at the same time.The pins aren't that clever,it doesn,t damage them.
Failing that you will have to drill into the lock face ,they drill dead easy as the metal is crap ,and the just pull off leaving the bolt underneath exposed.