Impossible to get FFLA Lines as replacment to normal landlines cause of cable Theft 4 months and counting

We are a business without 3 x telephone lines due to cable theft, i need to move our lines to sim cards - FFLA - Fixed Line lookalike numbers. Phoning the call centres, they tell me to go to a branch, once i go to the branch they tell me i need to phone in again??? Frustraded, Please direct me to the correct people / department please!!!!