Earlier this month I forgot to pay my Nationwide credit card bill and, big surprise, got hit with a £12.00 late payment charge.
What really annoyed me, however, were the 26 attempts Nationwide made to call me on my office and home phone numbers during the four days my payment was overdue.
I responded to the first call and made the payment, but, of course, the payment took two banking days to clear.
In the meantime, I'd programmed my home and office phones to divert to my mobile as I was on the road for a few days.
The total costs of the diverted calls has come close to a tenner as the auto-dialling system that Nationwide uses sits there waiting for a human voice to answer, even when it encounters a voicemail message on my mobile.
What the card issuers aren't making public, of course, is the fact that they have racks upon racks of auto-diallers to harass their customers into making payments.
Chatting with a pal in the trade, he tells me that MBNA is particularly forceful in this regard and contracts its harassing phone calls out to an Indian company called GVA Worldwide.
GVA Worldwide uses a combination of predictive auto-diallers and cheap Indian call centre operatives to call MBNA cardholders - who are late with their payments - on their home, office and mobile numbers until they make a payment via debit card over the phone.
According to some of the financial forums I've visited, GVA calls cardholders every few hours from 8am to 8pm seven days a week in a bid to get them to pay up.
The big question is why is MBNA so desperate to get its cardholders back on track? The reason is that the financial institution has parcelled its debts on the CDO (collateralised debt obligation) market that we're hearing so much about in the news.
If MBNA cardholders default en-masse, then these CDOs could hit problems. No wonder MBNA is getting so twitchy.
The only question I have is - if Nationwide is a mutual building society, then why is it following MBNA down the harassing phone call route?