Why is memebrship stuck on credit card page and won't update subscription after purchase?

After setting up authorize.net as a payment gateway and getting the ssl certificate I went to test the payment process. After putting in my credit card info I got this message: "Trial Occurrences must be less than Total Occurrences"

An email goes to me saying my purchase is complete and charges my card, but it doesn't leave the credit card page (and go to the welcome page) and the membership subscription doesn't update - I don't get the email with my username and PW and I don't get access to what I just bought.

Can you please tell me why it won't finish processing on the payment page and update the membership subscription and load the next page?