Apple ID disabled while studying abroad

Hello Everyone.

My name is Dejan. I've been living/studying in the US for 2 years before enrolling at a college in Serbia. Since then I have been spending around 4-5 months every year in the US, working during summer. Last year in June I bought an iphone 6s+ and created an apple ID. Everything worked great, I left for Serbia in October, and wasn't sure if I would be coming back to the US this summer, so I terminated my cell plan in the US before I left.

2 weeks ago, some suspicious charges have appeared on my Apple ID account, I contacted Apple via chat, explained the situation to them that I haven't made all those transactions, I changed my password and my Apple ID was working as usual. Few days later, my Apple ID was disabled. I contacted Apple once again via chat, explained everything, and they told me that I have to call the support in order to get it fixed.

Today I tried contacting them with a phone number from Serbia and via Skype, and they would hang up on me, as soon as I would explain it to them that I don't have a US cell number at the moment.

I am coming back to the US around mid-May, so I know I can get it fixed then, but is there anything I can do in this position? It really ***** not to be able to update/download apps...