我给打过电话，但没有打通。 The use of 过 (not experienced)
过 means: has done something
so 打过电话 means i have called him

in the mean time : 打了电话 means: i called him

the difference of the two chinese saying is: the first sentence is to emphasize that something is done by you, while "打了电话" or "打啦电话" is to telling a fact