This is worth a read
http://www.consumeraffairs.com/travel/aer_lingus.htm

There are other numbers on the site. Why not try using a dial thru or voip service to reach one of the international branches. For example the Hungarian number is a Budapest landline (the 1 gives that away) and can be dialled for 1p per min dial thru or free on voip. They speak very good english.

Perhaps someone else can advise.
Is the +353 818 365 044 listed on http://www.flyaerlingus.com/cgi-bin/obel01im1/Corporate/mission.jsp?BV_SessionID... the irish version of 0870? If not then perhaps this could be used instead.

Interestingly, when Aer Lingus started their operations in Hungary they also had a premium rate telephone number, as they still have in most other countries.  However, in Hungary the other airlines have geographic numbers and I expect it was sales considerations that made them change to a geographical number