Won't take my money

I may not have money tomorrow.. but I have it today.. I wanted to pay my mobile bill early. But they turn me away.. it was sad for the first time I felt off because I have to hope I have the money when they do finally allow me to pay .. on my app is says my bill will be 80dollars. I called and I couldn't even put 40 or pay the whole thing.. you know when a company have gotten to big and lost their way when they tell you or control when your allowed to give them funds for their service, even if you want to pay them now. I deal with 7 companies and this is the first time I'm dealing with a company that makes me wait to take my money.. I'm new to Comcast Mobile.. so I'm thinking of leaving. For the reason..I don't have peace of mind paying my bills early over here