VODACOM!!!

My moms phone stopped working(the changing port had an X) so I took it to the Vodacom store in gateway and the consultant advised that I should take it to the repair center so it will be done faster. I went to the Vodacom repair center in umhlanga and booked the phone in and the consultant that assisted me advised that the this is common in these phones. My mom received a message stating that the phone is ready for collection so my friend went to collect but to her surprise the phone was not repaired so she contacted me and I spoke to another consultant saying that the phone is not repaired due to water damage and it will cost R900 and something. The problem is that my mom did not drop her phone into water. The phone has never been around water so how is this possible? And the consultant did say this is common. This problem that she had occurred 2 months into having the phone and we waited for an hour and it charged again so this occurred again after months of having this phone and now it's a water damage. This is BS and I will not be paying for something that did not happen. I would like to be contacted immediately regarding this matter