**** about replacing part

I took my Ipad in to Time Zone Cellular on Friday and informed them that it was not charging (I tried 2 different chargers - one which was working with an iPhone). They informed me that the Ipad needed a new charging port and that it would cost R750 to replace. I collected my device later that day and it was charged and working. When I tried to charge it at home it didn't want to charge and I had a look at the port and it looked exactly like it did before (old with blue marks inside indicating corrosion). My gut told me that they hadn't replaced anything (at best they probably cleaned it). On Sunday I went to an authorised retailer in Menlyn and bought a new charger and asked them to inspect the iPad. In their professional opinion they confirmed that no part had been replaced and the back cover had not been removed. They showed me what a new part would look like and it contradicts the description that Time Zone gave me. I confronted Time Zone but they insist a new part was installed even though it's clear that the part still looks old. I asked to see the \old part"which they removed and they tell me that they threw it away. Lots of excuses - I believe they have de*****ed me."""