Huawei after sale service is a headache

I bought Huawei phone 2024, it has been giving me problems with some apps. Sometimes they work sometimes they just switch off, I took it to MTN they told me I have to take it to Huawei store. I took it to Huawei Sandton City. When I got there the lady told me she will not assist me, she will not even look at my phone because I did not buy it from them. What I do not understand is I went to there for technical assistance with their product why must I go to MTN. After trying to reason with her she finally looked at the problem and she was also surprised. This issue will help her in the future with the next customer who experiences the same problem When we buy phones they must let us know they do not offer after sale service.