Once registered online for eFiling, do I have to present myself in person at a SARS branch?

No you do not, you may be asked to get send SARS some documents, but they will send you a letter asking this. When did you register?

I registered on the 18th of May but am not sure what documents they might need. I registered previously in April and they deleted my account after 31 days. Please help??!!

Please go to your eFiling page, click on the returns tab and SARS correspondence and click search under all the options. Alternatively go to the user tab and see if there is an option for "pending registration", if so click it and there should be a letter waiting for you.

I tried to open that letter but it just keeps saying there is an error. Shall I try contact SARS in the morning or be persistant with trying to open that letter?

Try use Internet Explorer to open the letter.