We are in the English section, so we can assume he is in the UK or USA.
Paying your ISP in cash means you have a car to drive to your ISP and pay them.
It also means that you have an apartment or house for your ISP to wire up your connection.
It also means you have electricity, water, garbage, and rent.
There is no fucking way you or the op do not have a bank account, unless you are intentionally trying to live OFF the grid.
In the case of living off the grid, you would not have internet to your house, or electricity.
Sounds fishy to me.
It sounds like you're just utterly stupid. Or American.
I live in Australia, so you probably think that's somewhere near Seattle.
How the hell do you need a car to drive to your ISP? Ever considered the local Post Office takes cash payments? Not to mention there are hundreds of my ISPs stores around the country.
Have you even stopped to consider that the OP might speak English but lives in a country where Paypal doesn't support bank debits? No, you didn't. Because you think the entire world fits in the United States.
FFS, seriously.
So you are being Racist now?
And you are putting words in the OPs mouth.
He NEVER claimed that paypal rejected his bank. He said that he has NO bank account. Which is bullshit.
You are also stupid if you put cash in the mail.
You are just making EXCUSES by nagging at possible ways to explain how he has
1) A computer
2) an Internet connection
3) A house or apartment for internet
4) A power bill that comes with the house
5) A garbage bill
6) Rent or mortgage

Water bill
9) A job to pay for all those bills
10) You never noticed that I skipped number 7 because you are Australian.
All those things and no bank account? Bullshit.
You are going to invent possible ways that he lives an Amish lifestyle yet has the internet and no bank account. ha ha.. sure.