1. You should wait patiently for replies - asking within the same day or few days is kind of demanding
2. Digital software and online services is always risky - you should research BEFORE you do this kind of activity because you know that it's risky
3. For software stuff, people have posted something to the customer in the past and have used that as tracking proof.
4. If Paypal is asking for this information, chances are that you won't be reinstated - lots of stories about PP asking for this info and still keeping accounts suspended (I'm assuming that PP is asking for this - sorry if I am wrong)
you should send something tracked to the buyer.
i.e : Even send the paypal invoice/receipt to the buyers address with tracking, so you can add it to ebay/paypal.
Selling virtual items is high risk and can ALWAYS cause your account problems.
lots of accounts are lost selling these.
No tracking 
