Pathetic handling of problem

I am extremely frustrated at SAMSUNG VOC regarding a cell phone replacement. I had a problem with a unit which was replaced with a NOTE 4. I then contacted Samsung (Dorothy from Exchange) stating that the unit was not suitable. She then escalated to Sylvester from VOC. Sylvester first called me on the Thursday 23 April left a voicemail stating that he will call back. Nothing. I then followed up on 1 May when he stated that he will get back to be before the end of the day. Nothing. I called again today (7 May) and was once again assured that he will get back to me. Is this the level of client service from Samsung? I did state that the Note 4 (still in a sealed box) is way too large for me to handle and requested a downgrade to the S6. This problem has been dragging on since January this year. I have paid 5 months subscription and still do not have a working phone. Samsung global may be a great company, but Samsung SA is extremely disappointing. Where is the sense of customer satisfaction. This episode has left such a poor impression of Samsung that I am going to ensure that this is the last Samsung product I ever use!