The only way you ever get charged automatically is if you enable auto membership renewal.
http://community.48months.ie/t5/Most-Popular-Questions/Automatic-membership-renewal/td-p/32390/jump-...
Otherwise you just pay for membership, add-ons or cash credit topups when you want.
Note that unlike other pay as you go networks, on 48 you need membership (paid for up front) to use any services.
Having cash credit on your account is not enough.
And most services are covered by membership/add-on allowances and only a few are charged directly from your cash credit balance.
Read the FAQs if you are confused about how things work on 48.
Hope this helps.
