Not trustworthy and just plain bad service

I purchased a Samsung J1 Ace on the 17th Sept. The phone was not for my use so I never used the phone in any way. Two days later I returned the phone as the previous day I removed the phone from the box for the first time as I wanted to remove the sim card from the phone as the phone is for my cousin and she will use her own sim card. The sim card I first noticed wasn't put in properly and as I then further looked at the phoned I noticed the cover some how the bottom side is pushed through the middle cover, it was not in tact and also there was a small impact mark on that very side on the silver part. I know this is what indicates normally that the phone was dropped, which I know for sure didn't happen with the phone being in my care alone and no one else having access to the phone. I was told bluntly by the consultants that I dropped the phone which I find an unacceptable way to be addressed regarding the matter cause at no point do "you" have proof I let it fall...lest I was addressed as that it indicates the phone has fallen. There was a dispute between myself and the consultant that assisted me where I also told her that she never at any point showed me the phone to be like "have a look at the phone and you can see everything is fine, no scratches or any damage" just for making an example. She did give me the phone after she had put the sim card in and switched it on, I did tell her it can go back in the box because as said before its obviously not for me. on my part I didn't think anything could be wrong on the phone in this sense therefor I didn't feel the need to check for any faults. I do feel though this was the responsibility of the consultant to have me check the phone before I left the store. The phone was booked in to be sent to the repairs centre and last week I phoned to follow up , on two consecutive days I phoned to follow up and was promised a call back and never received a call...I remember on the second day a Faeeza called and said to phone back which didn't happen, I don't know the name of the consultant whom I spoke to the previous day. After I spoke to Faeeza I phoned back later after her call as she failed to phone back, I spoke to a manager who got who I believe is a supervisor by the name of "Rayno" to call me back later that day. I spoke to Rayno and I was told there is a quote on the phone which I made it clear I will not pay this as I was not going to pay for something I am not responsible for. I talked to him regarding concerns I mentioned before and also asked that I would rather want this matter to be investigated further and I was told he would get back to me...hasn't happened yet. I phoned today to find out the Vodacom repairs number that the phone was sent to, the number given "does not exist" and I phoned back, was told by consultant he will look for a other number as that was the number in the book, I did get frustrated as I said to him that this is the second incorrect number I was given by them for the repair centre and I don't understand how it is they don't know/have contact numbers for the repairs centres they work with and some not even knowing who they work with. I asked to speak to a manager and was told the manager is not available (not sure if he said he was on lunch or something) , he said he can take my details and will get the manager to phone me back and with this I said no that cause I don't believe that this call back will happen as promises to call back before failed and I am now frustrated to my limits for being messed around and need this process to be on the move.