Broken phone dispatched when taking out a contract.

I’m a 78 year old pensioner. I took out a contract with MTN telephonically on the 28th of August 2021. I do not normally trust telephonic sales, but I consented to this one because I’ve had a long standing relationship with MTN. The phone was delivered to me, however I did not receive a box for it. I switched on the phone a few times but it was freezing. I took it to an MTN shop and they kept the phone for over a year and told me that the problem must be referred to Samsung. I eventually took it to Samsung and was told that the phone cannot be fixed under the warranty as it has water damage. Please can you investigate what’s the situation with this phone, the fact that it came in no box, tells me the phone was faulty from the get go as it was not damaged by myself. I have been paying for this phone and the voice part for almost 2years now yet cannot use and have never been able to use the phone.