Pathetic service, not SLA compliant, poor communication.

Pathetic service lately, I requested to exchange one of two items I purchased, the correct item was scheduled to be delivered on the 2nd Dec and collect the exchange item. Till today, I have not received the item and it the one with me has not been collected. No communication was made with me, I’ve been the one trying to phone and their lines will keep you holding for an hour with no response, even emails are not being responded to. I’m disappointed to say the least. Why have a SLA in place and not comply?? How ***********!!