Who do I call to make sure my debit card is not charged on someone else's account

I used the free trail of Adobe awhile ago but somehow it didn't sign into my account the computer was signed into another persons account. I have absolutely no way of canceling this payment for a product I do not use. I don't even have a way to get a refund. Please help me.

That's not even my email my email is my name this is the second or third time this has happened. I'm literally so poor any dollar spent puts me at risk of not being able to afford rent or foor. Yes it's only $10 but every month and if other things like this happen it adds up and I could be down $100 by the end of the month. Please can someone help me.