It may just be another firm trying to sign you up for something in the same way as PPI, credit card debt write off, accidents firms try to get you. It's probably not illegal
Get call from people wanted to help me with debts all the time .My usual response is How did you get this number as it exdirect their response is that its on the system .what system are the talking about .Oh by the way I got no credit rating reason I dont borrow ,do with out what I cant afford and Im the baddie give us a break ...