purchase and withdrawal apparently the same thing

I had a double transaction go off my account. Both are same amounts. One was a purchase amount R420 the other a Withdrawal amount for R420. Now Absa obviously chose their smartest person to investigate this and have come up with it is a DUPLICATE TRANSACTION. Now the 1 transaction has no service fees to it, the withdrawal (done with no debit card people)has a service fee. Now Absa emails me they so sorry it was a duplicate transaction and my money will be deposited into my account shortly. Which transaction are they going to 'reverse'. I keep emailing action line it is not a duplicate because my bank statement shows 2 different transaction numbrs. I have had many duplicates happen to me and it reverses up to 24 hours later automatically. This so called duplcate was done on the 15th of April, we already on the 20th of April. I believe Absa is covering up. I believe a ********** activity has taken place and I am R100 poorer since I had to stop my card and get a new one and Absa charged me for that. How is this my fault. How is ***** my doing. I am not a happy client of Absa.