First, not being an American or based in the USA, I don't know if your issue is indeed because of your cellphone number. Speaking to agents (not just with Goldcar) doesn't always get the right answer because they can often be agency staff or poorly trained and may not have enough or the correct info to respond, but they'd sooner say something, anything to get you off the phone!

Second, and a bit more concerning is that very many of Goldcar's Italian agencies have an awful reputation. Just check out reviews and comments on any of Tripadvisor's Italy forums or ask there for help, anyway.

Yes, car rental prices are high and they can go up the closer you get to the pick up date, but - if some time away - may just go up and down owing to how many book that day.

Make sure you understand where you stand with included or added, without choice, insurances when you pick up the keys, whichever rental company you pick. And, if you need an automatic, make sure you book that - except luxury car categories, the default car will be stick shift/manual usually. Don't forget an IDP (easy to get from any AAA office or other sources) will be needed if stopped by the police, even if the rental company don't bother to check you have one.

As you are renting in Italy and presumably driving in Italy, especially make sure you know the rules of the road, and the most important think anybody needs to know about for Italy is the ZTL system. Each and every community/city/town has one and every one is different. If you cross the boundary without permission, you are fined each and every time and the rental companies are more than happy to ensure you get your fines, with their fees added on.

Oh, these last points apply to any rental company, not specific to just Goldcar.

Any specific or further question, usually on the Italy forums will help.

SWT