Yes, if you don't want to purchase online, then you will have to purchase Straight Talk Wireless Home Phone Plan at the store.
You can buy several cards at one time and put them in reserve. If you want to buy a six month supply of cards and put them in reserve, then you can. Then you would only have to refill every six months.
No. You could also:
1. Give them your checking acct routing number (which is on every check you write, so It's not a secret) and they can do an ACH payment from that account every month. If you decide to stop the service, just call them and withdraw your routing number payment method.
2. Buy multiple Service Cards and place them in your RESERVE account at ST. That Reserve lets you put as many months on service in an account from which they withdraw each month until it's used up. Some people stock their Reserve for 3 months at a time, 6 months, etc. or as many as you feel comfortable doing. Just write your refill date on your calendar so you don't forget to buy some more cards. Once you decide you really like this new phone system, you might even stock up a year's worth!? This method keeps all personal info, like CC#, routing #, etc., out of the system altogether.
I think you can do it online using a debit card, they will email you a code then you can enter that. Otherwise, you will have to go to the stroe, buy a card and then enter the code online.