Bad service @ Truworths

I am very unhappy with the service that i am receiving from Truworths.I had an account for more than 10yrs+ and wanted to purchase a cellphone.I phoned the call centre and i was told that i need to close my account and re open it again.I do not understand.My account was never in arrears and i have a credit limit of 12k.If im not trusted to purchase a cellphone why gave me so much credit to spend.Thats plain stupidity