Mtn nd Samsung

I bought a phone Samsung A52 s through mondo mtn last year November. On the month of April i returned the phone it has the problem of lcd nd screen frezing,it was under warranty. Before month end April the phone came back with the note idicating repaired.aftr days the phone started doing the same thing. I took it back around 16 May 2022 with me calling everytime for progress. I even called Samsung for advice as it is their brand.Mtn never called me it's me after them everytime. I called again nd they told me the phone is back at the shop went there yesterday to find out that my phone is opened no battery inside noone knows anything about it. Iam just frustrated not sure what to do iam paying for a phone iam not using