Jet Account/ Jet Club Cancellation

I am very disappointed at Jet retail store (Brits). I lost my Jet account Card and I went there today to pay using my Identity Document and they refused to help me. But last month I paid the account using the Identity Document. The account will be in arreas from tommorow and they just don't care. Please help me. I also cancelled my Jet Club last year but it seems like they didn't cancel it because I am still paying extra charges.