Anyone else struggling to get a smart meter to charge their EV cheaper

We moved house in October 2024 and I immediately reached out to our electric provider (Good energy) to fit a smart meter. Someone came out in January 2025 but said they couldn't do it as I have an old meter and I might have to wait up to 12 weeks. Despite chasing the energy company nothing has happened and it's costing me probably an extra £100 a month charging my EV. Anyone any tips on how if I could get it done quicker and if there's any point changing supplier.