Incorrect billing and non payment of refunds . National Security and Fire

On 2022.06.02 I signed a security contract with National Security and Fire for installation of an alarm system and armed response. I deposited R2000 into National Security and Fire account Dept. On 2022.06.06 I deposited an additional R2000 into National Security and Fire account Dept. Although the money was paid on 2.06.2022 the alarm was installed approximately 3 weeks later. When I requested when the additional passives and contacts which I have paid for on 6.06.2022 will be installed I was informed by the salesperson that there was a backlog in the installations and was not sure when the installation would be done. I requested a cancellation on the additional passives as more than 2 weeks had elapsed and no installation was done. I was informed by the sales rep that it would take approximately 3 weeks to get the refund. over 7 weeks have elapsed and I still did not receive a refund. The accounts department had requested for proof of payment which I have submitted but to date no refunds were made. Instead I have been billed for other items such as admin fees, armed response rental for June( although the rep has explained i would not be charged for June ), license fees, etc. The matter was escalated but matter was not resolved. I would like someone from management to resolve this issue as the Accounts dept clearly cannot resolve issue