Phone

I bought a Samsung A20 from Telkom agency... I just used the phone about 1 and half month then it start showing hearting warnings then it automatically shut down when I charged its show moisture can't charge but the phone was never wet etc... I took it in by telkom.. They send it to repairs but after two months I went to found out about the phone... At telkom store they told me it has never arrived they give me the repairs number to call.. Then I call them they told me that I must pay for the phone couse it has software fault n they found liquid on the phone...! My concern is the phone is on warranty and I never done any damage on the phone externally.... Just that the phone show me hearting signs then it's automatically shut down... But they say I must pay to fix the problem... And pay for quotation......