Pathetic customer service!

I require a letter which states that my account is up to date. I've app**** for a new cellphone contract and this letter is required. I've phoned Truworths four times already this week. Each time I am told that the request needs to go to the supervisor. This has still not been done. I've been a loyal customer for over 20 years, but after this experience I will be closing my account. So pathetic. Just one letter, that's all I requested.