Credit card: Fees or interest

I have an account with XXXX to add money for my childs school lunch. It is the Only way we can pay for school lunch. They charge a flat fee of {$3.00} every time I did money tot childs account. I can only afford to add {$20.00} at a time so the fee is a huge percent. In addition I have multiple kids, but they charge the {$3.00} on each child on each time I add funds. Additionally there is an upper limit and you can not add more than {$120.00} to the account at one time. When I had a debt on one of my accounts I could not pay off all at once to only pay one fee, they make you pay in chunks of {$120.00} max, collecting the fee each time. I submitted a form on the contact page with this feedback and got no reply.