Bitter poor customer service topped with dishonesty and petronise, at Vodacom Repairs in Mega city Mmabatho North West

Bitter poor customer service topped with dishonesty and petronise, at Vodacom Repairs in Mega city Mmabatho North West. 3 weeks ago I took my phone for screen repairs and to change battery that was nor charging, to my surprise all my information was wiped out. Nobody warned me that repairing a screen and changing a battery will lead to lost data. I went there and Tsholo said they replaced motherboard so she will get the old motherboard but first has to speak to Micheal who is the Manager. It's been 3 weeks already but every time I call am told Micheal is in a meeting and Tsholo is still busy so I must be patient. The information I need is vital so I humbly asked them to tell me if I have to do anything to get it but I was told they keep it in the store so I will get it. For the past 3 days when I call nobody answers, they have identical so they ignore my calls. I replaced the screen before and no information was lost, why this time around? My heart is sore and broken, it will be highly appreciated if they can give me back the part that stored my information so that I can retrieve it.