IPhone 5 complain

I took my phone to Vodacom repairs yesterday, my phone is working very nice the problem is the charging point, after buying the phone i had the same problem with the phone and the problem disappeared, and it come back again recently and i had to take it back to vodacom yesterday, 1st time i took it to Apple store in Mernlyn and i was told that its only charging point, the problem is the phone doesnt charge when its on for you to charge it you need to turn it off and it will charge that's the only my consent, so today i received a call saying i need to pay R3000.00 for the phone to be fixed i wonder why bcos its a contract phone why should i pay the answer was theirs physical damage, when i ask how come they told me they dont knw,again the problem its a charging point and the unit charge when its off, why telling me about physical damage?why telling what i dont know, the same reason i left MTN TO Voda thinking they are good in serving their customer, im so disappointed with the way they are dealing with my issue,i told them that my phone is working my problem its a charging point,i knw they will come up with other stories just like MTN meaning i have to move another network now.