Samsung A70 overheating

I purchased a Samsung Model SM-A705FZBNXFV on the 25 July 2019 by means of a contract at Vodacom Vaal Mall, Vanderbijlpark. (assistent WERNER). Recently, 28 Dec 2019 I reported that the phone overheats and battery life does not exceed a couple of hours. The instant reply from the service provider (Werner) was that due to moisture ingress, via the USB port, the phone is now useless. They undertook to send it to "Samsung" for an assessment and that certain costs would be involved. NOW I've been a proud, loyal and serious owner and user of SAMSUNG phones for a VERY long time and its been the first instance that I've experienced such an error/fault on a SAMSUNG. Cer*****ly the new release of A70 should not misbehave in such a manner? The instrument is utilized for bussiness purposes and now I was handed a low cost, inadequate phone as a peace gesture while I have to await in suspense the inevitable answer from Samsung? Given the situation and the care I practice with my personal belongings, especially my pride and joy(Samsung phone), I do believe that a replacement for this instrument should be considered by the manufacturer, as part of the 24 month Warranty period! Be so kind as to give me advice on this matter?