Refusal of refund

I had a contract with Chubb who later changed their name to National security and Fire since 2012. We have had a few cases where the panic alarm was activated due to intruders on the property. Initially, we had outstanding service as they sub contracted a local security company for patrol. Since they changed their name, service had deteriorated drastically. Due to their lack of service, we decided to cancel in October 2020. We were advised that the 1 month notice period would apply to which I agreed. On 1 October 2020, we were charged for the yeearly radio fee. As we cancelled, I requested a refund of the radio fee as I am now liable to pay a radio fee to the new service provider. To date, Natioanl have failed to refund me. They have called and also sent out a representative to collect their radio but no refund. National are poor service providers and I would highly recommend anyone to stay away from them.