Actually I got my digisave converted to preferred 2 years ago through funding. Later when I gave my hdfc details to employer it got converted to salary account code 113 automatically.
Two months ago I got offer to upgrade to imperia. So I don't think salary criteria matters.
Same with me. Using it from past 4 works absolutely ok.
I requested replacement for niyo debit card and received visa platinum debit card, confirmed it with customer care its absolutely free of charge.