Complaint on bad Service from the store manager

I sent a complaint to Hello Peter for bad service and the following day the Joshua Doore Manager called me saying i should go to the shop and take a new fridge because the one i bought gave me problems within the first week of purchase. I went there on the 20th November and collect it,the one i bought before was R7999 and this time i took the one for R6599. I did not receive the change because they told me that their system was offline but every time i call them they tell me the same story and the funny part is i did not receive any papers or receipt stating that i did an exchange.. Please help me as i do not understand how a system can be offline for so many days..