First I want to ask, what download and upload speeds are you paying Charter for? When you bought one of their plans they would have advertised the download and upload speeds for the price you are paying.
To make sure you are getting accurate numbers here is a thorough test you can perform using multiple test sites.
Step 1: Using any browser, Delete your web browser cache, history, cookies, everything.
Step 2: Test your Internet on each of the 3 sites I linked you to below (Do not use your VPN). Test them 1 at a time. Mark down what all of them rated download and upload speed.
Step 3: Again, fully Delete web browser cache, cookies, history, everything.
Step 4: Log into your Private Internet Access VPN
Step 5: Test your Internet speed on the same 3 sites again. Mark down what speeds you got.
* After you are finished post here what speeds you got for all 3 sites without using the VPN and when you used the VPN