Unexplained charges, credit disappearing and no customer service.

I have been trying to get a response and solution from STss for over a month now about unexplained charges and credit 'disappearing' from my wallet. I have tried to decipher their statements which make no sense, and make it impossible to prove that there are discrepancies in their metering and charges. I have called and emailed so many times to no avail. This seems to be a larger problem.