Hi there! I understand you bought 3,500 worth of data (11GB valid for 7 days) via the YangaPlug app yesterday, but it hasn't been credited to your line yet. Let's get this sorted out for you.

To start, could you confirm a couple of things for me?
1. Did you receive any confirmation message from YangaPlug after the purchase? Sometimes there's a delay in the network updating.
2. Is your device currently showing any data balance at all, or is it still the same as before?
3. Have you tried restarting your phone or toggling airplane mode on and off to refresh network signals?

While I wait for your answers, here’s a simple step you can try:
- Check your data balance directly with your network provider using the USSD code or their official app, just to see if it reflects there differently.
- If you don’t see the data, open the YangaPlug app, go to your purchase history or wallet section to verify the transaction status. If the payment went through but data isn’t credited, the app may have a glitch syncing with the network.

If you have already tried these or the problem persists, the next step would be:
- Log out and log back into the YangaPlug app to force a refresh.
- Clear cache data of the app via your iPhone's Settings > General > iPhone Storage > YangaPlug > Offload App (this won't delete your data but refreshes the app storage).

Lastly, if nothing changes, you might want to contact YangaPlug support directly via their email ([email protected]) or within the app’s help section as it could be a backend delivery issue to your specific line.

Let me know how it goes or if you need help with any of these steps! Are you satisfied with this guidance so far?