Lock changed and not working

I would like to complain about this company as they are the worst service provider and their business must be investigate as they reap people off. On the 29 June 2023 Iog a call with them and they changed my lock and put in an old lock which is giving problems, when I call them they are rude and told me to fix it, the lock has rusted and i paid R3423, 50 for a bad lock. this company must stop abusing us as their client