Stop harassing me

The harassment I have been experiencing from you all is insane. I rented fiber extenders from you for 4 years. hen I cancelled my contract with you, you sent a courier to collect the devices who was unprofessional on so many levels and downright inconsiderate. I sent you all a mail and let you know he had flaked on collection TWICE and that I was not to blame. You then sent me a mail on the 15th of May to return the package to my nearest postnet. Which i dully did on the 22nd of May (I work for a living so couldn't just rush off to return your package due to your sloppy courier). You then sent me a bill for the devices on the 23rd of May. Stay with me now - I had already done the return the day before. You then debited me on the 25th for said devices. I unpaid it, because I no longer have your devices meaning you have taken my money ********ly. I called, your finance department said I need to relax and wait they would acknowledge receipt when the devices were received. Up until today, you are still harassing me and sending me failed notices and CHARGING ME FEES FOR THE DEBIT ORDER REVERSAL. Are you people thick? I have several emails and calls to you stating I have returned your devices with proof from postnet but still you harass me. Why the hell would I want to ***** your pathetic old devices? I also find it funny that you would charge clients the value of new ones for depreciated assets - wondering how that works from a consumer protection perspective. Now please, seeing as you do not bother to respond to any of my mails and act stupid when I call, leave me alone and do your jobs before I take this to the consumer council and the bank for you debiting my account ********ly for the amount you did.