Hello

It might have occurred because of  traffic on the site(which usually happens when a lot of people are trying to register at the same time )
You can try to clear the cacheand try to reload the page wait to check if the payment status has changed. If it doesnt change I will advise you to wait for a day as sometimes it takes time.
Hopefully it will change by that time and if it doesnt then you will have to register again. You can use a different and more secure payment gateway this time.
Probably the previous payment (the one which did not make it to the form submission) will be refunded in 3-5 working days.