DEBIT CARD EXPIRY WOES AT ABSA- WHY?

My wife's debit card will expire soon. Can somebody tell me why a Debit card expires?????????? She went to the bank with her ID, but was not able to finalise the new card's issue because she did not have a proof of address, but she was able to do financial transactions up to a second before she app**** for a new card? What a farce!!! On the next visit she presented her Edgars Statement, but this was not accepted because only her surname appeared on the statement. Bear in mind that she's been a client of ABSA for 35 years and has Money Market funds invested. So I was summonsed to the bank with my ID. I had to sign an "Affidavit" nogal, without there being a Commissioner of Oaths present, to confirm my address. Now, for the 3rd or 4th time my wife had to put her two thumbs on the Biometrics scanner. Eventually the computer system was blamed and my wife was requested to come back to the bank again to have the transaction completed. It would have been easier to open a bank account at another ban****! Please tell me why a debit card expires??