still getting payslip after resignation

I have quitted my part time job recently, yet my former employer still sending me payslips on weekly basis. acting like if they were still paying me. after some digging that shows I will have to ask them to stop doing that in writing. I am curious that why are they doing that, is there any benefits like tax deduction or something? any help would be greatly appreciated. kevin

UPDATE: Ever since this post I have contacted them for P45 and not yet having any response

Hi ,
 

Please contact Personal Taxes on 0300 200 3300 who can check that your employment record is correct .

Thank you .