Thank you, this is just what I need!

Not sure what i'm supposed to do with these guys. In the past few months i've had loads of calls, 2 letters and now i've got a letter from a solicitors saying I have 7 days from the date on the letter to pay a paypal fee of £34.34 which i've checked on my paypal and can't find anything I've had no letters or phone calls from Paypal and no proof that I actually owe the fee from Intrum. I've tried to contact Intrum but haven't got a reply. What should I do?

I've had 2 phone calls from IJL saying I owe £35 to paypal. The first call I received the man on the phone was really aggressive, demanded my credit/debit card details but didn't tell me anything or why I owed the £35 when I said I wouldn't give him my details he asked for my mobile number and that he'd be in touch. Second call, I got about 10 minutes ago. I was told I HAD to pay it in full and that paying by debit/credit card was the safest way to pay but I still haven't been told what i'm actually paying, all I know is that it's for paypal which I rarely use unless I get something off Ebay which isn't very often. He gave me a reference number which he told me i'd have to use if I choose to pay by cheque or giro. I haven't received a letter, just phone calls with men demanding my card details. I've looked on my paypal account to see if there's any information about it but can't find anything there, so i've e-mailed them. What should I do?