Vodacom unfair Client treatment

we took up a Vodacom Contact in October 2018, this was a Samsung S8, this contact was take with an insurance cover take at the Vodacom store(Finrite), my husband then had his phone ****** and a case was opened at the police and we received a case number, we have since been in a Deadlock with Vodacom as they have introduced a betterment fee of R3173.03 over and above the excess that needs to be collected from us. According to Vodacom the handset we had taken up (Galaxy S8) has been discontinued and they can only offer the Galaxy S9, Vodacom is not treating the client fairly in this regarding we are being forced to pay for a phone we do not want, why are we not given options that on the same level as the S8 that we had taken up, asking a client to pay an extra amount because their supplier has stopped producing the phone type is unacceptable. Calling there call centre line does not help as the agent drop the call once we ask to speak to the manager! They have never come back to us, we constantly need to go to the Northgate branch and never given the customer service we deserve we will gladly close the contact, we are not asking for any additional benefits, just want we have been paying for, the phone is covered for 10k,