Paying for a Services, not received

I have recently moved houses and at my new place of residence, the signal is poor to non existing. I logged a complaint with Cell C who sent out a technician to my residence. She conducted signal tests with an app used by Cell C for this purpose and informed me that there is no data reception and that calls lasts for 20 seconds before being dropped by the network. This report was given to Cell C and I received a call from them today, informing me that they admit there is poor to no network coverage but they can unfortunately not install a booster as my monthly spend is not enough. We have 3 Cell C contracts in our household with a combined spend of +R2500.00 per month. I therefore want to cancel all my household contracts (without penalty for early cancellation) and port them to MTN who commits to installing boosters for their clients. I am paying for a service which I can not enjoy and therefore this is a breach of contract. I will lodge a complaint with ICASA should Cell C not respond to my complaint.