Angry customer

Good day I went to vodacom repairs in sandton city for them to check my phone because it had a network problem but instead for them to fix it they destroyed it more now my phone is blacklisted. I don't even know how or who blacklisted my phone they also don't know but when i took it to them it was fine... On top of that they charge for an unfixed phone.. I'm really angry because i had t leave my sick son and go to the police station to do an affidavit of something i don't know off... My contact number is ********** 234. Your assistant will be highly appreciated..