Not Fixing of cellphone thats still under guarantee

I bought a Huawei Y7 on 20th March 2019,. December 2019 the phone didn't want to take the password nor the fingerprint keep on asking for password but you cant tap on the screen. Phone came back Vodacom said that they not going to fix it because the glass screen is **** and that someone has been working on the phone it cost 1400 to fix. My question why would I be so stupid to let someone work on the phone while the phone is still under guarantee i told them that is unacceptable so now that you actually telling me that Vodacom is selling **** Huawei cellphone/parts. They send the phone back for the second time than it came back new problem the cellphone got wet some damp issue how the hell the phone never fell in the water so they don't cover damp/wet. This all happened at Vredenburg Vodacom West coast Mall. Never ever will I make use of Vodacom again it was my last I've been with them for more than 8years the first time something like this happened your customer service is so so bad.