Is Citigroup trying to preserve cash by stiffing some of its vendors?

The other day a vendor for Citibank, the national banking arm of the defacto US taxpayer-owned bank, told me how Citi might be playing games with some of the companies that do busines with it. This vendor says he always used to get his bills paid within 30 days of submitting them to Citibank. But recently it too more than 60 days for a bill to get paid.