Truworths

I receive emails and messages from Truworths offering me vouchers to use when I buy on my account. so I assume I am still a Truworths customer even though my account is paid up. Yesterday I decided I would buy a Cell phone. I phoned before I went to the store to confirm if I could buy a cell phone on my account and what I needed to bring. Was told yes I could. Arrived at Truworths Musgrave and chose the phone. Only to be told that I haven't used my account for some time so cannot purchase a cell phone however they are happy for me to purchase clothing for R2000 but not a cell phone for R1999 . Please could someone reply to this question as what the difference is. I have more than enough credit available on my account.