Today I received a new email from the customer service rep that has been handling my issue. The rep indicated that the problem I've been having is a known issue that has been affecting other members as well, and their IT people are working to correct the problem. The rep indicated that some modifications had been made to my account to reactivate it. I'm now able to see new surveys in my dashboard, and have been completing surveys with no further problems, both on the e-rewards website and in the app. I will cautiously report that it looks like things are back to normal, and this was NOT a situation where my account had been deliberately locked out.