Loan recovery

one of my clients , had taken loan in her mother-in-law's name from Barclays bank in Raipur,Chattisgarh way back in 2007.but the last few loan instalments were pending and the bank was closed and also the bank account in which we transferred the amount was closed(as online money transferred got returned back).there was no further communication but now some recovery agent is calling my client and threatning her to return the amount.As searched on 'google.com' it seems that the recovery agency is fraud.please suggest where/to whom should my client contact for this issue?