Get an answering machine at this location. 15 calls, no answer

Like: Everything outside of trying to contact this location by phone was great. When speaking with the customer representative, he gave me a free upgrade on my next rental - which is great for next time. I also got a free upgrade when I got there. So everything worked out in the end.
Dislike: I tried calling about 15 times between 10:00AM and 2:00PM to see if I could pick up my car early, no one answered the phone. I was told they were short staffed, that's fine, but it's 2018. Give me a voice-over or something that's telling me what's going on.