Shocking service

My Samsung suddenly stopped charging so took it in to "All Fix" Leaping frog. They replaced the charging port for R650. Phone was charging but like 1% an hour right through the night then battery depleted again after an hour.. Went back a another 2 times with no avail and the only way I could charge my phone eventually was with a wireless charger - but still slow.. My husband then took it back and they said it is probably the battery.. He then paid another R650 to replace the battery but still made no difference. This time the phone had a 6 month warranty so went back again. Only to be told that the screen is now gone and it went when they opened up the phone!!! Now I must pay again to fix the screen!!!?? The warranty doesn't cover screens apparently and so they don't take any responsibility I refuse to put any more money in as can just about buy a new phone already and what guarantee does one have that it will even work...? ?