Unacceptable

Last year I bought two Nokia Asha phones. One on contract and one prepaid. The one phone was for my mother, I bought it specifically because her only requirement was that she could use the phone for whatsapp. A few months ago the phone started giving her trouble she's always had issues with the memory even though she has a 2G memory card. Now she is unable to use whatsapp, she can't save anything and she is unable to even make a phone call. I took the phone to MTN and briefly explained what the problem was, the sales assistant did not wait for me to finish and started telling me that \this is a problem that these phones have....nokia is not making the software for the phone to be able to support whatsapp and that even though the phone is just over a year old it is basically useless". Because I was waiting so long and I was tiered due to the fact that I am seven months pregnant I just did not have the strength to question what he was telling me and I just walked away. After some thought I remember that the other phone I bought that was exactly the same also have problems with memory but none of the other issues. Which made me think that the 'story' I was told is a load of bull a"""