... just wait until she initiates contact. She may have genuine reasons... if it's a one off situation.
If a guy ignored my texts and calls and it was consistent behaviour, that would be a deal breaker for me. I'd assume he felt indifferent about towards me. Someone who is genuinely interested will be excited and go out of their way to message you and take your calls
You should remember it’s important to remain cool, and text in a laid-back way. Don’t fall into the same traps that most men do; being needy, full of complaints, or pissed off at a girl for not replying; you’ll be sure of not getting a reply.
Of course it may seem impolite that she hasn’t responded, but remember to her you’re a stranger. She doesn’t know that much about you so there isn’t any point in getting pissed off. It will scare her off for sure.
Being sad and needy is even worse. You want to be seen as an attractive, popular guy, so wait a few days before texting her, and don’t write anything like ''I just want to talk to you, blah blah blah”. Manliness is what girls find most attractive and being needy is not very appealing.
Try being nonchalant and treat her like anyone else. Because that’s exactly what she is! It isn’t the first number you’ve ever gotten, so if she doesn’t respond, it’s her loss.
After a few days try again without caring too much about it.