Declined Purch 412

When i look at my bank statement i keep being charged for "Declined purchase"yet i didn't make any transaction nor have debit orders on my account for the dates these "declined purchase"are made. Now this increases my bank charges as im being charged R8.50 per purchase for something that isn't even my fault, im very upset by this!

I feel as if FNB is protecting me, as last month debit order of R285 went through on my account which i have never authorised!