Alright thank you. How can i be sure that Moorcroft doesnt have access to my bank account, if i canceled the DD on the phone call it should be alright, no?

Hello everyone, i have a sticky situation with Paypal. i sold item online and i got scammed ( will not get into details ) but paypal chose buyers side and put my account into 411gbp debt. I didnt do anything about it because i was left without my item and money, until few days ago i realised that paypal passed my case to the Moorcroft debt company, i have received few emails from them in the past month or so but havent replied or anything ( as i didnt see that ) till yesterday when i called them and set up direct debit to pay it back, but then i checked few topics here where it was advised to do nothing and so i called them back to cancel the direct debit.. My question is what should i do and what happens if I continue to not replying to Moorcroft and paypal..