@stephenhatfield first , your plan details show shows the new 4G plan details immediately after it was charged, there is no 48 hours wait
The new speed will take as many as 48 hours to activated
In terms of " I noticed today that I'm still on my original 3G plan (which has less data).", it could be just a cache issue and your browser is not showing the updated information from the system. Try to login to My Account using incognito mode, or a completely different browser (Edge/Firefox/Chrome) or even a different device. You should see everything showing the new plan with the new data limit
Check your credit card. Have you been charged for both plans? Did you schedule a change plan on next renewal to the 4G plan? If you have both plan charges on your credit card contact customer support and ask for a credit for the 3G plan charges. If the double charge occurred solely thru autopay have the CSA open a ticket with the tech team to investigate the cause.
.....never mind I thought both charges were from July 24th.....
To contact customer support : Submit a support ticket via SIMon the chat bot Click here
Or if you cannot submit a ticket via SIMon thenClick here ....for additional member supplied info.